What organ is part of both the respiratory system and the digestive system?

The pharynx is the correct answer because it serves as a common passageway for both the respiratory and digestive systems. Located in the throat, the pharynx connects the nasal cavity and mouth with the esophagus and larynx. For the respiratory system, the pharynx allows air to pass from the nasal cavity to the larynx and then into the trachea, facilitating breathing. Simultaneously, it directs food and liquids from the mouth to the esophagus, thus playing a crucial role in digestion as well. This multifunctional aspect of the pharynx differentiates it from the other listed structures, which primarily serve a single system. The esophagus is solely part of the digestive system; the trachea is exclusively related to the respiratory system, directing air to the lungs; and the larynx primarily functions in voice production and air passage without involvement in digestion.