Which of the following BEST characterizes many cancers such as colorectal cancer?
A)They result from the activation of one critical tumor-suppressor gene. B)They result when the transition from G2 to M in the cell cycle is inhibited. C)They result when DNA replication during the S period of the cell cycle is inhibited. D)They result from a series of sequential mutations in a number of genes. E)They result from decreased expression in a series of cellular oncogenes.