**Core Concept**
Hyperventilation with 6% CO2 in inspired air leads to respiratory alkalosis, a condition characterized by an increase in blood pH due to excessive elimination of carbon dioxide (CO2). This occurs because CO2 is a partial pressure that affects blood pH through the bicarbonate buffer system.

**Why the Correct Answer is Right**
When CO2 is inhaled, it diffuses into the bloodstream, where it reacts with water to form carbonic acid (H2CO3), which then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-). In the case of hyperventilation with 6% CO2, the excess CO2 is rapidly eliminated, leading to a decrease in the concentration of hydrogen ions and an increase in the concentration of bicarbonate ions. This results in a decrease in blood acidity and an increase in blood pH, causing respiratory alkalosis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the scenario of hyperventilation with 6% CO2 in inspired air.

**Option B:** There is no direct relationship between hyperventilation with 6% CO2 and the development of lactic acidosis, as this condition typically occurs due to anaerobic metabolism and tissue hypoxia.

**Option C:** The scenario of hyperventilation with 6% CO2 does not directly lead to the development of metabolic acidosis, as this condition is characterized by an increase in the concentration of acidic substances in the blood.

**Clinical Pearl / High-Yield Fact**
In clinical practice, it is essential to recognize the signs and symptoms of respiratory alkalosis, which can include tetany, muscle cramps, and numbness or tingling in the extremities. These symptoms can occur due to the increased concentration of calcium ions in the blood, which can lead to neuromuscular excitability.

**Correct Answer: C. Respiratory alkalosis.**