The correct answer is b) pharynx.
The pharynx is a muscular tube that connects the nasal cavity and mouth to the esophagus and larynx. It plays a crucial role in both the respiratory and digestive systems. When you swallow, the pharynx helps guide food and liquids from the mouth down to the esophagus while also allowing air to pass from the nasal cavity to the larynx and lungs.
In contrast, the larynx primarily serves as the voice box and plays a role in directing air into the trachea, while the trachea and bronchus are mainly involved in air passage only, not food. Thus, the pharynx is unique in serving as a passageway for both air and food.