Why Should Data That Is Obtained by Asking Adolescents to Self-Report

Why should data that is obtained by asking adolescents to self-report whether they are still virgins be interpreted with caution?

A) Adolescents are likely to lie about whether they are still virgins.
B) Adolescents are likely to give the response that they think the researcher wants to hear.
C) It is dependent on how adolescents interpret what it means to be a "virgin."
D) There is a selection bias, with substantial between-person differences between those who choose to answer this question and those who typically leave this question blank.