Carter is sorting out his priorities for the week. Of the priorities he's listed below, which one could be completed later?

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.