Which of the following is known as the "voice box" in the respiratory system?

The larynx is referred to as the "voice box" in the respiratory system because it contains the vocal cords, which vibrate to produce sound when air is expelled from the lungs. The larynx plays a crucial role not only in speech production but also in protecting the trachea against food aspiration. It is located at the top of the trachea and serves as a passageway for air while also facilitating the act of swallowing.

In contrast, the trachea is primarily a conduit for air to reach the lungs, the nasal cavity is involved in filtering, warming, and humidifying air as it is inhaled, and the pharynx serves as a shared pathway for both respiratory and digestive systems. Each of these structures has distinct functions, but the larynx uniquely integrates the processes of respiration and phonation.