Cancer can result from a variety of different mutational events. Which of the following is least likely to result in the initiation of a cancerous tumor?(A) A receptor mutation results in activation of a cell-division pathway in the absence of the appropriate ligand.
(B) A mutation results in the loss of the ability to produce a tumor-suppressor protein.
(C) A defect in a cell-cycle checkpoint prevents a cell from entering the S phase.
(D) At the anaphase checkpoint, separation of chromatids occurs without all centromeres