
To identify the marked region in the presented spirometry, we need to understand the components involved in lung volumes and capacities. Spirometry is a test that measures lung function, specifically the volume and/or speed of air that can be inhaled and exhaled. Here's a brief explanation of the given options:
In the context given, the correct answer is Functional Residual Capacity (FRC), as it represents the volume of air remaining in the lungs after a normal expiration.


