**Core Concept**
The partial pressures of alveolar gases in the lungs are determined by the diffusion of gases between the alveoli and the blood, as well as the ventilation and perfusion of the lungs. The partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2) in the alveoli are influenced by the partial pressures of these gases in the arterial blood and the rate of gas exchange.

**Why the Correct Answer is Right**
The correct answer is based on the concept of alveolar-arterial oxygen gradient (AaDO2), which is a measure of the difference between the alveolar partial pressure of oxygen (PAO2) and the arterial partial pressure of oxygen (PaO2). The PAO2 can be calculated using the alveolar gas equation: PAO2 = (FiO2 x (Pb - PH2O)) - (PaCO2 / R). The Pb is the barometric pressure, PH2O is the partial pressure of water vapor, and R is the respiratory quotient. The PAO2 is typically higher than the PaO2 due to the diffusion of oxygen from the alveoli into the blood.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the relationship between partial pressures of alveolar gases.
* **Option B:** This option is incorrect because it does not take into account the factors that influence the partial pressures of alveolar gases, such as the rate of gas exchange and the ventilation-perfusion ratio.
* **Option D:** This option is incorrect because it is a general statement that does not provide specific information about the partial pressures of alveolar gases.

**Clinical Pearl / High-Yield Fact**
The alveolar-arterial oxygen gradient (AaDO2) is an important measure of gas exchange in the lungs, and an increase in AaDO2 can indicate conditions such as pulmonary edema or chronic obstructive pulmonary disease (COPD).

**Correct Answer:** C.