Please Read the Paragraph Below to Answer the Following Question(s)

Please read the paragraph below to answer the following question(s) .
Jim has become particularly interested in the genetic basis of cancer and has spent considerable time reading published papers about oncogenes. He learned that as early as 1972 researchers suggested that mutations in proto-oncogenes caused by carcinogens can convert them to oncogenes. He asked you to answer a couple of questions about this because he did not have the biology background to totally understand.
-Jim learned that some cancer cells produce more growth-stimulating proteins than others.What would you give him as a plausible explanation?

A) Tumor suppresor genes may have been activated in these cells.
B) Proto-oncogenes may have mutated to become oncogenes in these cells.
C) Mutations in homeotic genes may be responsible.
D) This may result from vitamin C and vitamin E deficiencies.