What is the result of testosterone on male laryngeal development?

Testosterone plays a significant role in male laryngeal development, particularly during puberty. The hormone contributes to the elongation of the vocal cords, which is a primary reason for the deeper voice observed in males as they mature. This elongation occurs due to increased growth of the laryngeal structure under the influence of testosterone. As the vocal cords lengthen, they produce lower frequencies when vibrating, resulting in the characteristic changes of the male voice.

In contrast, the other options do not specifically describe the effects of testosterone on the laryngeal development process. While other elements, such as size and shape of related structures like the epiglottis and trachea may undergo changes during puberty, they are not directly attributed to testosterone's action in the same way as the elongation of vocal cords. Therefore, the correct answer reflects the specific influence of testosterone on vocal cord development and the resulting impact on voice pitch.