**Core Concept**
Radiation exposure is a significant concern in medical imaging and therapy. The risk of radiation-induced damage increases with the dose and duration of exposure.

**Why the Correct Answer is Right**
The correct answer is related to the concept of radiation dose and its impact on biological tissues. Ionizing radiation can cause DNA damage, leading to mutations and cancer. The risk of radiation-induced cancer increases with the dose and duration of exposure. In medical imaging, the dose is usually measured in millisieverts (mSv) or grays (Gy). The maximum radiation risk is associated with procedures that involve high doses of radiation, such as fluoroscopy or interventional radiology.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a procedure or modality that involves high doses of radiation. While computed tomography (CT) scans do involve radiation, they are not typically associated with the maximum radiation risk.

**Option B:** This option is incorrect because it does not provide a specific procedure or modality that involves high doses of radiation. Radiation therapy is a treatment modality that involves ionizing radiation, but it is typically used in controlled doses to target cancer cells.

**Option C:** This option is incorrect because it does not specify a procedure or modality that involves high doses of radiation. Chest X-rays are a common imaging modality that involves low doses of radiation.

**Clinical Pearl / High-Yield Fact**
To minimize radiation exposure, clinicians should use the lowest dose necessary for the diagnostic or therapeutic goal, and consider alternative imaging modalities that do not involve ionizing radiation, such as ultrasound or magnetic resonance imaging (MRI).

**Correct Answer:** C.