Answer:
A. vital capacity
Explanation:
Vital capacity is defined as maximum amount of the air that a human can expel from lungs after the process of maximum inhalation. In other words, its is the volume of the lung which represents the maximum of the total volume which can be exchanged with the air.
It can be measured by using a wet or a regular spirometer. A normal adult has between 3 to 5 litres of VC. Vital capacity of the human depends on the age, sex, mass, height and ethnicity.
