Research on 12th-Graders Indicates That

Research on 12th-graders indicates that

A) significantly more males than females are sexually active (i.e. ,have had at least one sexual encounter) .
B) significantly more females than males are sexually active (i.e. ,have had at least one sexual encounter) .
C) both males and females tend to be sexually active (i.e. ,have had at least one sexual encounter)  
D) neither males nor females are sexually active.