Answer: A. Cells can divide uncontrollably.
Explanation:
If the p53 gene is damaged, tumor suppression is reduced. A cell with damaged DNA may proceed with its division. The daughter cells produced are likely to inherit mutations due to the unrepaired DNA of their mother cell. Over many generations, cells tend to accumulate mutations. These mutations result in a p53 protein, and DNA damage can accumulate in cells which means it will not able to control cell proliferation because it is unable to trigger apoptosis. Such cells may continue to divide in an uncontrolled way, leading to tumor growth. This means people who inherit only one functional copy of the gene (or none) will most likely develop tumors.