Question

a social network usually acts as a support system for its members. it helps members maintain good physical and mental health or prevent physical and mental breakdown. it also reduces the risk of dying prematurely or committing suicide. there are several reasons for this. our social network of friends, relatives, and coworkers can make us feel good by boosting our self - esteem despite our weaknesses and difficulties. because they are more objective than we are about our problems, they can open our eyes to solutions that we are too emotionally distressed to see. the companionship from our network, strengthened by our frequent participation in recreational activities, can bring us joy while chasing away loneliness and worries. finally, our friends and relatives often give us instrumental support—money and other aid—to help us cope with our problems. all these social and psychological factors have an impact on our bodily health. they keep our blood pressure and heart rate at low levels by reducing our brain’s secretion of stress hormones.
in contrast, our loved ones place many demands on our time and personal resources. they can irritate us by criticizing us or invading our privacy. this is shown in a study of the social networks of 120 widows. in this study, the women reported that more than two - thirds of the people who made their lives more difficult were their friends and relatives. in fact, these negative experiences may drag down people’s sense of well - being more than the positive social support can raise it up. negative encounters usually have a stronger impact than positive ones; an argument stands out against a background of pleasant experiences. thus, an isolated friendly exchange at a wedding that is already filled with strife between in - laws can restore only a little peacefulness. on the other hand, a single heated exchange at an otherwise tranquil wedding can ruin the whole experience. in sum, social networks can have both positive and negative consequences for people’s lives.
which sentence best expresses the main idea of the second paragraph?
a weddings can be difficult experiences.
b an argument can have a stronger effect than a positive encounter.
c people’s social networks can have negative effects on them.
d a revealing study was done of the social networks of 120 widows.

Explanation:

The second paragraph starts by contrasting loved ones' demands (negative impacts) and then gives a study example. It then discusses how negative social encounters (like arguments) have stronger effects than positive ones, and how social networks can have both positive and negative consequences. Option C says "people’s social networks can have negative effects on them" which aligns with the paragraph's focus on negative impacts (along with positive) but the main idea here is about the dual (positive and negative) but the key part of the second paragraph is also about negative effects? Wait, no, let's re-examine. The second paragraph: "In contrast, our loved ones... can irritate us... negative experiences may drag down... negative encounters usually have a stronger impact... a single heated exchange... can ruin... In sum, social networks can have both positive and negative consequences..." Wait, but the options: A is about weddings, B is about argument vs positive encounter, C is about negative effects, D is about a study. Wait, the second paragraph's main idea? Wait, the first part of the second paragraph talks about negative impacts (loved ones irritating, study showing more difficult with friends/relatives), then negative experiences vs positive, then examples of negative (argument) and positive (friendly exchange) in weddings, then conclusion that social networks have both. But the question is which sentence best expresses the main idea of the second paragraph. Let's analyze each option:

A: Weddings can be difficult experiences. But the paragraph uses weddings as an example, not the main idea. Eliminate.

B: An argument can have a stronger effect than a positive encounter. This is a detail (about negative vs positive encounters), not the main idea. Eliminate.

C: people’s social networks can have negative effects on them. The paragraph does discuss negative effects (irritation, dragging down well - being, stronger negative impacts) along with positive, but the main idea includes both? Wait, no, the start of the second paragraph is about negative impacts (loved ones' demands, study on widows), then negative vs positive encounters, then examples, then conclusion that social networks have both. But option C is about negative effects. Wait, maybe the main idea is that social networks can have negative effects (since the paragraph spends a lot on negative: irritation, study, negative encounters' stronger impact, etc.). Let's check the conclusion: "In sum, social networks can have both positive and negative consequences for people’s lives." But the options don't have a "both" option. So among the options, C is about negative effects, which is a major part. Let's check the options again. Option C: "people’s social networks can have negative effects on them." The paragraph does discuss negative impacts (loved ones irritating us, the study showing more difficult with friends/relatives, negative experiences having stronger impact, etc.). So C is a good candidate.

D: A revealing study was done of the social networks of 120 widows. The study is an example, not the main idea. Eliminate.

So the best answer is C.

Answer:

C. people's social networks can have negative effects on them.