Correct Answer: Birds

Solution : The correct option is - Birds.

Syrinx is the voice-producing organ found in birds. It is located at the base of the trachea where the trachea splits into the bronchi. Unlike mammals, which have a larynx (voice box) located higher up in the throat, birds have a syrinx, which allows for a wide range of complex vocalizations. This adaptation enables birds to produce the varied and often intricate songs that are characteristic of many species.