Which of the following best explains why the natural family planning method should be used by long-term couples only?

a.

this method is the least effective method of all birth controls.

b.

this method requires the couple to be prepared for a child.

c.

this method protects against numerous stis.

d.

this method is 100% effective if done correctly.

Which of the following statements concerning cancer and mutations is correct? a: cancer can only occur with a mutation in a somatic cell. b: usually, multiple mutations are required in different genes to cause cancer. c: none of the other answer options is correct. d: cancer can only occur with a mutation in a germ cell. e: usually, a single mutation is all that is required to cause cancer.