Best answer gets to be !
what is the best way for teenagers to avoid hiv infections?
a. using a condom during most sexual encounters
b. having sex with only two or three different partners
c. having oral sex instead of sexual intercourse
d. abstaining from sexual activity

answer; i believe the correct answer is (secondary prevention);

well when looking at this if you think about it   negativley and positivley   react with each other and when the first layer gets full they add layers it starts with 2 on the first layer and it constantly goes on until the official number is there