## Core Concept
The question tests the understanding of respiratory physiology, specifically the relationship between alveolar ventilation rate and the levels of carbon dioxide (CO2) and oxygen (O2) in the blood. Alveolar ventilation is crucial for gas exchange, removing CO2 from the body and adding O2.

## Why the Correct Answer is Right
An increase in alveolar ventilation rate enhances the exchange of gases in the lungs. This means more CO2 is expelled from the blood into the alveoli and subsequently exhaled out, and more O2 is absorbed from the inhaled air into the blood. The primary effect relevant to the question is the decrease in the partial pressure of carbon dioxide (pCO2) in the arterial blood. This is because increased ventilation blows off more CO2. Therefore, with an increase in alveolar ventilation rate, there will be a decrease in arterial pCO2 levels.

## Why Each Wrong Option is Incorrect
- **Option A:** This option suggests an increase in arterial pCO2, which is the opposite of what occurs with increased alveolar ventilation. Increased ventilation would not cause an increase in CO2 levels in the blood.
- **Option B:** This option implies no change in arterial pCO2 levels, which contradicts the physiological response to increased alveolar ventilation. An increase in ventilation does affect gas exchange and blood gas levels.
- **Option D:** This option suggests an increase in arterial pO2. While increased ventilation can lead to an increase in oxygen saturation under certain conditions (like high altitude or respiratory failure), the direct and most immediate effect of increased alveolar ventilation on blood gases is related to CO2 levels.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **hyperventilation** (an increase in alveolar ventilation rate) leads to **respiratory alkalosis** due to decreased pCO2 levels in the blood. This condition can result from various causes, including anxiety, fever, or mechanical ventilation. Recognizing this relationship is crucial for interpreting arterial blood gas results and managing patients with respiratory issues.

## Correct Answer: C.