**Core Concept**
Gamma irradiation is a process used to inactivate the lymphocytes in blood products, thereby reducing the risk of graft-versus-host disease (GVHD) in transfusion recipients. This is particularly important for patients with weakened immune systems, such as those undergoing chemotherapy or bone marrow transplantation.

**Why the Correct Answer is Right**
Gamma irradiation uses ionizing radiation to inactivate the lymphocytes in blood products. The process involves exposing the blood product to a controlled dose of gamma radiation, which damages the DNA of the lymphocytes and prevents them from proliferating. This reduces the risk of GVHD, a potentially life-threatening complication of blood transfusion. The gamma radiation does not significantly affect the function or viability of the other blood cells, such as red blood cells, platelets, or plasma.

**Why Each Wrong Option is Incorrect**
**Option A:** Ultraviolet (UV) light is not typically used for irradiating blood products, as it may not be effective in inactivating lymphocytes and may also cause damage to other blood cells.

**Option B:** Beta irradiation is not commonly used for blood product irradiation, as gamma radiation is more effective and easier to control.

**Option C:** X-ray irradiation is not typically used for blood product irradiation, as it may cause more damage to the blood cells than gamma radiation.

**Clinical Pearl / High-Yield Fact**
To ensure the safety of blood transfusions, blood products are often irradiated with gamma radiation to inactivate lymphocytes and prevent graft-versus-host disease.

**Correct Answer:** C.