Final answer:
Research indicates that many adolescents use contraceptives only sporadically, while nearly 90% use some form of birth control. Friends often discourage the use of condoms, but it is not stated that boys are more likely than girls to suggest contraceptive use.
Step-by-step explanation:
The research on contraceptive use in adolescents indicates that many use contraceptives only sporadically, making answer c the correct option. While nearly 90% of adolescents use some form of birth control (a), it has been found that friends often discourage the use of condoms (b). Additionally, it is not stated in the research that boys are more likely than girls to suggest contraceptive use (d).