**Core Concept**
The ventilation-perfusion (V/Q) ratio in the lungs determines the exchange of gases between the air we breathe and the blood. A decrease in V/Q ratio indicates a mismatch between ventilation and perfusion, leading to inadequate oxygenation of the blood.

**Why the Correct Answer is Right**
When the V/Q ratio is decreased, it means that there is more blood flow to a particular area of the lung than ventilation. As a result, the alveoli are not adequately ventilated, leading to a decrease in the partial pressure of oxygen (pO2) in the blood. Additionally, the increased blood flow without adequate ventilation leads to a decrease in the partial pressure of carbon dioxide (pCO2) in the blood as it is being washed out. This is because the increased blood flow allows for more CO2 to be removed from the alveoli, despite the decreased ventilation.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because a decrease in V/Q ratio would lead to a decrease in pO2, not an increase.

**Option B:** This is incorrect because a decrease in V/Q ratio would lead to a decrease in pCO2, not an increase.

**Option C:** This is incorrect because a decrease in V/Q ratio would lead to a decrease in pO2, not an increase, and a decrease in pCO2, not an increase.

**Clinical Pearl / High-Yield Fact**
A decrease in V/Q ratio can occur due to various factors, including pulmonary embolism, pneumonia, and atelectasis. It is essential to remember that a decreased V/Q ratio can lead to both hypoxemia (low pO2) and hypocapnia (low pCO2).

**Correct Answer:** B. Decreased pO2, decreased pCO2.