Health Clubs Typically Experience an Increase in One-Year Memberships in January

Multiple Choice

Health Clubs typically experience an increase in one-year memberships in January, but many new customers cancel their memberships before the end of the year. Which of the following is the best explanation for this behavior?

A) Some health club members suffer minor injuries that prevent them from working out.
B) Some people are overly optimistic about their future behavior.
C) Some people fail to treat their membership fees as sunk costs.
D) Some members receive utility from activities they believe are popular.