If Expiratory Reserve Volume = a , Residual Volume = B , Tidal Volume = C and Inspiratory Reserve Volume = D, then Funtional Residual Capacity (FRC) is equal to

Options

A. A + B
B. A + B + C
C. B + D
D. A + B + D

Answer

To solve the problem, we need to understand the definitions of the different lung volumes provided in the question and how they relate to the Functional Residual Capacity (FRC).

### Step-by-Step Solution:

1. **Identify the Given Volumes:**
- Expiratory Reserve Volume (ERV) = A
- Residual Volume (RV) = B
- Tidal Volume (TV) = C
- Inspiratory Reserve Volume (IRV) = D

2. **Understand Functional Residual Capacity (FRC):**
- Functional Residual Capacity (FRC) is defined as the volume of air remaining in the lungs after a normal expiration. It is the sum of the Expiratory Reserve Volume (ERV) and the Residual Volume (RV).

3. **Formula for FRC:**
- FRC = ERV + RV

4. **Substituting the Values:**
- From the given information:
- ERV = A
- RV = B
- Therefore, substituting these values into the formula gives us:
- FRC = A + B

5. **Conclusion:**
- The Functional Residual Capacity (FRC) is equal to A + B.

### Final Answer:
Functional Residual Capacity (FRC) = A + B

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