**Core Concept**
Glomus cells are specialized cells found in the carotid body and aortic body, which are part of the chemoreceptor system. These cells are responsible for detecting changes in the levels of oxygen, carbon dioxide, and pH in the blood, triggering a response to regulate breathing and cardiovascular function.

**Why the Correct Answer is Right**
The correct answer is related to the function of glomus cells in detecting hypoxia (low oxygen levels). Glomus cells contain oxygen-sensitive chemoreceptors that respond to decreases in oxygen levels by releasing neurotransmitters, such as ATP and dopamine, which stimulate the carotid sinus nerve and trigger a response to increase breathing and blood flow to the brain. This response helps to compensate for low oxygen levels and maintain homeostasis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because glomus cells are not typically associated with the regulation of blood pressure.
**Option B:** This option is incorrect because glomus cells are not involved in the regulation of respiratory rate in response to changes in temperature.
**Option C:** This option is incorrect because glomus cells are not primarily responsible for the detection of carbon dioxide levels in the blood.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that glomus cells play a critical role in the detection of hypoxia and the regulation of breathing, and that dysfunction of these cells can lead to conditions such as congenital central hypoventilation syndrome.

**Correct Answer: C. Carotid body tumors