Question

read the paragraph about social media.
social media outlets are often criticized as forums for unimportant postings and uniformed rants. though much of what is posted is conversational drivel, social media outlets also serve as springboards for entrepreneurs. creative people can advertise their designs or products at a low cost to a wider market than entrepreneurs could have imagined in previous generations. the internet is the ultimate free marketplace, allowing motivated individuals to share their wares with the world.
what is the controlling idea?
every entrepreneur should advertise ones products on the internet.
the internet has countless forums on which people share meaningless posts.
social media has a valid purpose as an inexpensive, creative marketplace.
advertising products on the internet is inexpensive compared to television.

Explanation:

The paragraph starts by mentioning the criticism of social media (unimportant postings), then uses "though" to introduce its positive side (serving as springboards for entrepreneurs, allowing advertising at low cost to a wide market). The controlling idea should capture both aspects (initial criticism and then the positive, valid purpose).

• The first option is too one - sided (only about entrepreneurs advertising, not the overall view of social media).
• The second option only focuses on the negative (meaningless posts) and ignores the positive.
• The fourth option only compares advertising cost (not the overall role of social media).
• The third option "Social media has a valid purpose as an inexpensive, creative marketplace" encompasses the positive aspect (after the "though") which is the main focus of the paragraph's controlling idea.

Answer:

Social media has a valid purpose as an inexpensive, creative marketplace.