Answer:
Cricoid.
Explanation:
Larynx is also known as voice box and lies above the trachea. Larynx helps in the protection of pharynx while swallowing the food.
Cricoid cartilage is the inferior wall cartilage of larynx. This is a ring shape in structure and present at the back part. This provides the attachment site for muscles, bones and cartilage.
Thus, the correct answer is option (d).
