**Core Concept**
The ventilation-perfusion (V/Q) ratio is a critical concept in respiratory physiology, representing the balance between the airflow (ventilation) and blood flow (perfusion) in the lungs. It is essential for maintaining adequate gas exchange, as it affects the delivery of oxygen and removal of carbon dioxide.

**Why the Correct Answer is Right**
The V/Q ratio is typically around 0.8 in healthy individuals, which means that for every 100 ml of air inhaled, approximately 80 ml of blood is perfused to the alveoli. This balance is achieved through the autonomic regulation of airway resistance, lung compliance, and pulmonary blood flow. The V/Q mismatch can occur due to various factors, such as pulmonary embolism, pneumonia, or chronic obstructive pulmonary disease (COPD), leading to hypoxemia and hypercapnia.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as the V/Q ratio is not directly related to the respiratory rate. While the respiratory rate can affect the ventilation, it does not directly impact the perfusion of the lungs.
* **Option B:** This option is incorrect as the V/Q ratio is not typically measured in terms of oxygen saturation. While oxygen saturation can be affected by the V/Q ratio, they are not directly correlated.
* **Option C:** This option is incorrect as the V/Q ratio is not a fixed value and can vary depending on the individual's condition and the presence of lung diseases.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the V/Q mismatch can occur in various lung conditions, and it is essential to assess the V/Q ratio in patients with respiratory symptoms to guide appropriate management.

**Correct Answer: C. 0.8**