question: Q:A 55-year-old male with a 60 pack-year smoking history presents to his oncologist for ongoing management of his recently diagnosed small cell lung cancer. His oncologist discusses several options and decides to start the chemotherapeutic medication, etoposide. The patient is warned that one side effect of this drug is myelosuppression so he should be vigilant for development of any infectious symptoms. The beneficial effect of this drug in treating cancer is most likely due to which of the following effects?? 
  {'A': 'Alkylation of DNA', 'B': 'Crosslinking of DNA', 'C': 'DNA intercalation', 'D': 'Inhibition of supercoil relaxation', 'E': 'Stabilization of microtubules'},