Which of the following would be most likely to lead to cancer?
A. amplification of a proto-oncogene and inactivation of a tumor-suppressor gene.
B. hyperactivity of a proto-oncogene and activation of a tumor-suppressor gene.
C. failure of a proto-oncogene to produce a protein and amplification of a tumor-suppressor gene.
D. hyperactivity of both a proto-oncogene and a tumor-suppressor gene.
E. failure of both a proto-oncogene and a tumor-suppressor gene to produce proteins.