Chapter 5.B, Problem 7QQ

Imagine that a survey of randomly selected people finds that people who used sunscreen were more likely to have been sunburned in the past year. Which explanation for this result seems most likely?

a. Sunscreen is useless.

b. The people in the study all used sunscreen that had passed its expiration date.

c. People who use sunscreen are more likely to spend time in the sun.