Question

which cranial nerve innervates the sternocleidomastoid and trapezius?
abducens
facial
vagus
accessory
trigeminal

Explanation:

The accessory nerve (cranial nerve XI) is responsible for innervating the sternocleidomastoid and trapezius muscles. The abducens nerve (cranial nerve VI) innervates the lateral rectus muscle of the eye. The facial nerve (cranial nerve VII) innervates the muscles of facial expression. The vagus nerve (cranial nerve X) has a wide range of functions including innervating many organs in the thoracic and abdominal cavities. The trigeminal nerve (cranial nerve V) is involved in sensation from the face and motor innervation to the muscles of mastication.

Answer:

Accessory