A Patient, Diagnosed with Cancer, Has Been Receiving Radiation Treatments

A patient, diagnosed with cancer, has been receiving radiation treatments to shrink the tumor. After several weeks, the patient tells the nurse that he does not need as much pain medication as before. What would explain the reduction of pain for this patient?

A) The radiation treatments reduced the size of the tumor and pressure on adjacent tissues.
B) The tumor is secreting pain-control chemicals initiated by the radiation.
C) The patient is getting used to having pain.
D) The patient's pain receptors have been affected by the cancer.