**Core Concept:** Peripheral and central chemoreceptors are specialized cells in the body responsible for detecting changes in blood gases and regulating respiration accordingly. Central chemoreceptors are located in the medulla oblongata, while peripheral chemoreceptors are found in carotid and aortic bodies. Increased ventilation helps maintain blood pH and oxygen levels.

**Why the Correct Answer is Right:** The correct answer is C, Carbon Dioxide (CO2). Increased CO2 levels activate peripheral chemoreceptors, leading to the release of excitatory neurotransmitters and increased respiratory frequency and depth, which collectively result in increased ventilation. This helps in maintaining normal blood pH and oxygen levels.

**Why Each Wrong Option is Incorrect:**
A. Hypoxia - Hypoxia refers to insufficient oxygen levels, which stimulates peripheral chemoreceptors, but the correct answer is CO2, not oxygen.
B. Hypercapnia - Hypercapnia refers to increased CO2 levels, which stimulates peripheral chemoreceptors, but the correct answer is CO2, not hypercapnia itself.
D. Hyperventilation - Hyperventilation is the increased ventilation caused by CO2, peripheral chemoreceptors, and central chemoreceptors, not the cause itself.

**Why Option C is Right:** Carbon Dioxide (CO2) is the correct answer because it is the stimulus that activates peripheral chemoreceptors, leading to increased ventilation. CO2 is a potent respiratory stimulant, and its increase activates peripheral chemoreceptors, resulting in central respiratory stimulation and increased ventilation. This process helps maintain normal blood pH and oxygen levels.

**Clinical Pearl:**
Understanding respiratory regulation is crucial for maintaining a patient's homeostasis, especially in critical care and emergency situations. Adequate respiratory rate and depth are vital for oxygenation, ventilation, and overall patient well-being.