abstinence is the only birth control method that has a zero percent failure rate for an unplanned pregnancy and 100 percent rate of protection against stis.

Ithink the answer is c.  hope this is right and

Afew buddies come over to your house to hang out. they notice you're struggling in school, perhaps you have to rely on to pass your class, but you can't absorb the knowledge. they could positively reinforce getting a tutor and working with you, dedicating more time to the areas of struggle and less on hanging out to better yourself.secondly, say you're the victim of bullying. you're afraid to tell an adult because of possible repercussions from the bully himself. your friends encouraging you and pushing you towards telling an adult for your safety is another example. 

Hiv can be transmitted through oral sex. you can get hiv through vaginal fluid and semen. if you have an open sore or cut in or near your mouth and an you get the semen or vaginal fluid of an infected person in those cuts or sores, you can get hiv