4. The writer thinks the best way to cheer people up is a. to buy them a gift. b. to share a smile or a laugh. c. to give them a good grade.

Решение:

В тексте говорится: "If a person is sad, the best thing to do is share a smile or laugh. It is the easiest (and cheapest) way to cheer someone up."

Ответ: b. to share a smile or a laugh.