A powerful predictor of which students would engage in early sexual activity was

A) remembering learning about sex in health classes.
B) availability of a steady boyfriend or girlfriend.
C) access to contraceptive information.
D) intention, influenced by the belief that one's friends were doing it.

Research has shown that one's intention to engage in early sexual activity is strongly influenced by the belief that one's friends are doing so. This social pressure can override other factors such as access to contraceptive information or learning about sex in health classes. Availability of a steady boyfriend or girlfriend can also be a factor, but it may not always be present for all students.