Which of the Following Is NOT a Reason We Think

Which of the following is NOT a reason we think that cancer is a genetic disease?

A) Exposure to mutagens such as chemicals or ionizing radiation often leads to cancer.
B) Some families have a disproportionally high number of family members with cancer compared to the general population.
C) All cancers develop due to changes during gametogenesis.
D) Certain types of cancer often share the same chromosomal abnormalities.
E) Most cancers result from accumulation of somatic mutations.