Functional Residual Capacity (FRC) is the volume of air present in the lungs at the end of passive expiration. It represents the balance between the inward recoil of the lungs and the outward recoil of the chest wall. The value of FRC varies depending on age, sex, height, and body composition.

The correct answer is option 'A' which is 2100-2300 ml. Let's discuss the factors affecting FRC and how they determine the value of FRC.

Factors affecting FRC:

1. Age: FRC increases during childhood and adolescence, reaches a peak in early adulthood, and decreases in old age. This is because of the reduced elasticity of the lungs and chest wall with aging.

2. Sex: FRC is higher in males than females because of their larger lung volumes and greater chest wall compliance.

3. Height: FRC is directly proportional to height because taller individuals have a higher lung volume and greater chest wall compliance.

4. Body composition: FRC is lower in obese individuals because their excess body fat puts pressure on the diaphragm and reduces lung volume.

Calculation of FRC:

FRC can be measured using various techniques such as helium dilution, nitrogen washout, and body plethysmography. The normal range of FRC in healthy adults is between 2100-2300 ml. However, this value can vary depending on the individual's factors mentioned above.

Conclusion:

In conclusion, the value of FRC is determined by multiple factors such as age, sex, height, and body composition. The normal range of FRC in healthy adults is between 2100-2300 ml. Any deviation from this range may indicate a respiratory disorder or disease.