Having a Representative Sample Is Most Important in Which of the Following

Having a representative sample is most important in which of the following example claims?

A) "Fifty-nine percent of college athletes feel that playing professionally is an attainable goal."
B) "Expressing uncertainty about relationship commitment prior to marriage is associated with greater marital happiness."
C) "Having a boss compliment you at work causes you to work more efficiently."
D) "People who have religious experiences report feeling more comfortable with the idea of death."