**Core Concept**
Radioresistance refers to the ability of cells to resist the damaging effects of ionizing radiation. This property is crucial in understanding the effects of radiation on living organisms and in cancer treatment. Cells with a high capacity for DNA repair, low mitotic activity, and a compact cell structure tend to be more radioresistant.

**Why the Correct Answer is Right**
Lymphocytes, specifically T cells and B cells, are among the most radioresistant cells in the body due to their low mitotic activity and high capacity for DNA repair. Lymphocytes have a compact cell structure, which helps to protect their genetic material from radiation damage. Additionally, lymphocytes have a unique ability to repair double-strand breaks in DNA, making them more resistant to radiation-induced damage. This property is essential for their function in the immune system, allowing them to survive and respond to radiation exposure.

**Why Each Wrong Option is Incorrect**
**Option A:** Stem cells are highly sensitive to radiation due to their high mitotic activity and lack of DNA repair mechanisms, making them a poor choice for radioresistance.
**Option B:** Cancer cells, particularly those with high mitotic activity, are highly sensitive to radiation and often undergo rapid cell death in response to radiation exposure.
**Option C:** Neutrophils, a type of white blood cell, are highly sensitive to radiation and undergo rapid apoptosis (programmed cell death) in response to radiation exposure.

**Clinical Pearl / High-Yield Fact**
Lymphocytes are highly radioresistant due to their compact cell structure and high capacity for DNA repair, which allows them to survive and function in the presence of ionizing radiation.

**Correct Answer:** C.