**Core Concept**
The overdrive mechanism during hyperventilation is a physiological response to rapid and deep breathing, where the body attempts to compensate for the excessive loss of carbon dioxide (CO2) from the bloodstream. This mechanism is mediated by the respiratory center in the brainstem, which responds to changes in blood pH and CO2 levels. The overdrive mechanism involves an increase in the sensitivity of the chemoreceptors, leading to an increase in respiratory rate and depth.

**Why the Correct Answer is Right**
During hyperventilation, the rapid loss of CO2 from the bloodstream leads to a decrease in blood pH, causing an increase in the concentration of hydrogen ions. This decrease in blood pH stimulates the chemoreceptors in the carotid bodies and aortic bodies, which are sensitive to changes in CO2 and pH levels. The stimulation of these chemoreceptors triggers an increase in the sensitivity of the respiratory center, leading to an increase in respiratory rate and depth. This overdrive mechanism helps to compensate for the excessive loss of CO2 and restore normal blood pH levels.

**Why Each Wrong Option is Incorrect**
**Option B:** This option is incorrect because it does not accurately describe the overdrive mechanism during hyperventilation. The overdrive mechanism is not primarily mediated by the autonomic nervous system, but rather by the stimulation of chemoreceptors and the increase in sensitivity of the respiratory center.

**Option C:** This option is incorrect because it does not accurately describe the relationship between hyperventilation and the overdrive mechanism. The overdrive mechanism is not a result of the body's attempt to conserve CO2, but rather to compensate for the excessive loss of CO2 from the bloodstream.

**Option D:** This option is incorrect because it does not accurately describe the physiological response to hyperventilation. The overdrive mechanism involves an increase in respiratory rate and depth, not a decrease.

**Clinical Pearl / High-Yield Fact**
The overdrive mechanism during hyperventilation is a classic example of a physiological compensatory response to changes in blood pH and CO2 levels. This mechanism is essential for maintaining normal blood pH levels and preventing the development of respiratory alkalosis.

**Correct Answer:** C.