Correct Answer: B
Hint: "proto-" means "original" or "primitive" --> like a PROTOtype is an original design idea for a product
When a proto-oncogene mutates it can become an oncogene (a gene that, when expressed, blocks normal cell death and therefore allows an irregular cell to continue to survive and proliferate). Cancerous tumors can then form as this cell continues to grow uncontrollable and divide.
