In human beings, `CO_(2)` concentration in the inspired and expired air is respectively

Options

A. 0.03% and 5.3%
B. 0.4% and 5.%
C. 0.04% and 3.0%
D. 0.03% and 4.0%

Answer

To solve the question regarding the concentration of carbon dioxide (CO₂) in inspired and expired air in human beings, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Respiration**:
- Respiration in humans involves two main processes: inhalation (inspiration) and exhalation (expiration). During inhalation, oxygen is taken into the body, and during exhalation, carbon dioxide is expelled.

2. **Identify the Concentration of CO₂ in Inspired Air**:
- The concentration of carbon dioxide in the air we inhale (inspired air) is approximately 0.03%. This is because the atmosphere contains a very low concentration of CO₂.

3. **Identify the Concentration of CO₂ in Expired Air**:
- The concentration of carbon dioxide in the air we exhale (expired air) is significantly higher, approximately 3.8%. This increase is due to the metabolic processes in the body that produce CO₂ as a waste product.

4. **Match the Concentrations with Given Options**:
- The question provides several options for the concentrations of CO₂ in inspired and expired air. Based on our findings:
- Inspired air: 0.03%
- Expired air: 3.8% (which can be rounded to approximately 4% for matching with the options).

5. **Select the Correct Option**:
- From the options given, the pair that matches our findings is 0.03% for inspired air and approximately 4% for expired air.

### Conclusion:
- Therefore, the correct answer is:
- Inspired air: 0.03%
- Expired air: 4%

### Final Answer:
- The concentration of CO₂ in inspired and expired air in human beings is approximately **0.03% and 4%**, respectively.