A Nursing Student Asks a Nurse How Cancer Cells Become

A nursing student asks a nurse how cancer cells become resistant to methotrexate [Rheumatrex]. The nurse is correct to respond by saying that cancer cells acquire resistance to methotrexate by:

A) reduced production of transporter that pumps methotrexate out of cells.
B) reduced synthesis of dihydrofolate reductase.
C) reduced uptake of methotrexate into cells.
D) increased ability to convert the drug to a polyglutamated form.