2. Which of the following statements are correct?

I. The alveoli in the respiratory system is the site of gas exchange in the body.

II. Air is filtered, cleansed and cooled in the trachea of the respiratory system.

III. The bronchioles are finer subdivisions of bronchi which connect to the air sacs.

IV. The diaphragm is a muscle used in breathing that separates the lungs and stomach.

A. I, III & IV only C. I, II & III only

B. II, III & IV only D. I, II & IV only
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