ANATOMY

Detailed explanation-1: -Answer and Explanation: The correct option is b, gas exchange.

Detailed explanation-2: -The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.

Detailed explanation-3: -The larynx and lungs are parts of the human respiratory system. Diaphragm helps in expansion of thoracic cavity during breathing. However, the heart does not have any role in breathing.

Detailed explanation-4: -The nasal cavity functions to humidify, warm, filter, and act as a conduit for inspired air, as well as protect the respiratory tract through the use of the mucociliary system.