Which of the following is not a true statement about birth control?
a. some forms of birth control are less effective for teens.
b. it doesn't matter which form of birth control a person uses because they all have the same level of effectiveness.
c. birth control must be used correctly to be effective.
d. using birth control does not guarantee that a teen is safe from becoming pregnant.

Explain why methicillin resistant staphlococcus aureus (mrsa) is more prevalent now than it was only 30 years ago. a. antibiotics cause mutations in staphlococcus aureus that lead to an increase in the number of methicillin-resistant strains. b. methicillin resistance causes an infection to spread more rapidly. c. frequent and inappropriate use of methicillin-type antibiotics has provided selective pressure that has resulted in an increase in the proportion of methicillin-resistant strains of staphlococcus aureus. d. diseases like aids have made people more vulnerable to infections from staphlococcus aureus.