Final answer:
The device that measures the volume of inspired and expired air is called a spirometer (Option B).
Step-by-step explanation:
Lung volumes are measured by a technique called spirometry, which is crucial for diagnosing various respiratory diseases. For instance, spirometry test results include measurements like the forced expiratory volume (FEV), which is how much air a person can force out of their lungs in one second, and the forced vital capacity (FVC), the total amount of air that can be forcibly exhaled.
The FEV1/FVC ratio obtained from these measurements can help diagnose conditions such as asthma, emphysema, and fibrosis. A high FEV1/FVC ratio suggests lung fibrosis, while a low ratio is characteristic of asthma. Thus, spirometry is a vital tool in both the diagnosis and monitoring of respiratory conditions.
Thus, the correct option is B.