Cricothyroid is supplied by:

Ans. A. External laryngeal nerveThe cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage, and its action tilts the thyroid forward to help tense the vocal cords. This muscle is the only laryngeal muscle innervated by the superior laryngeal branch of the vagus nerve known as the external branch of the superior laryngeal nerve.