One Reason Cancer Therapy Often Fails Is That the Targeted

Multiple Choice

One reason cancer therapy often fails is that the targeted cells become resistant to the drugs that are supposed to kill them.Which of the following is the most likely mechanism of this resistance?

A) Carrier proteins block diffusion of the drugs into the cancer cells.
B) Membrane proteins pump nutrients into the cancer cells.
C) Drugs diffuse into the cancer cells via simple diffusion.
D) Membrane proteins actively transport the drugs out of the cancer cells.
E) Channel proteins pump ions into the cancer cells.