The gene that causes cancer upon mutation is called as

Mutagens are physical/ chemical/ biological agents that can cause heritable changes in genetic material (mutation), for example, UV rays, X-rays, $?$ rays, formaldehyde, etc. Oncogenes are the mutated form of genes that mostly govern the process of cell growth. But the mutated form disturbs cell division and cause cancer. These genes, directly or indirectly, control the rate of cell growth. For example, Bcl-2. that codes for apoptosis inhibitor but the mutated form causes B-cell cancers. A self-replicating independent hereditary gene that is present in the cytoplasm is called as plasma gene. So, the correct answer is B.