Respondents of the national college health assessment who were sexually active indicated that were the most commonly used forms of birth control.

Condoms and birth control pills

Respondents of the National College Health Assessment who were sexually active indicated that condoms and birth control pills were the most commonly used forms of birth control.

Birth control is any method employed to avoid pregnancy. There are several forms of birth control which include the use of condoms, IUDs, birth control pills, the rhythm method, and vasectomy. Condoms and birth control pills are the most common forms.

Birth control pills are medications taken to prevent pregnancy. These pills contain hormones which prevent sperm from meeting an egg, thicken the mucus on the cervix and stops ovulation. There several  types of birth control pills.

Condoms are small stretchy pouches that are worn during sexual intercourse. Condoms prevent sperm from moving into the vagina. Hence, it helps to prevent pregnancy and also sexually transmitted diseases (STDs).

the correct answer is:

a population changes in response to a change in the environment.

it creates acid rain