A Tumor Suppressor Gene DIFFERS from an Oncogene in That

A tumor suppressor gene DIFFERS from an oncogene in that

A) the presence of a normally functioning protein product from a tumor repressor gene is required to initiate oncogenesis.
B) the presence of an altered protein product from a tumor suppressor gene is required to initiate oncogenesis.
C) deletion of both alleles is tumorigenic for an oncogene but may not be for a tumor suppressor gene.
D) deletion of both alleles is tumorigenic for a tumor repressor gene but is not for an oncogene.
E) amplification of a tumor suppressor gene results in oncogenesis.