Question

what do studies show about people who are happier?
they will have strong opinions.
they will be unpleasant to be around.
they will live longer.
they will buy more electronics.

Explanation:

Research in psychology (a subfield of Social Science) and related health studies show that happiness is associated with better physical health and increased longevity. Having strong opinions, being unpleasant, or buying more electronics are not consistent with findings about happier people.

Answer:

C. They will live longer.