![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
A person receives a shallow knife wound just behind the sternocleidomastoid muscle and about 1 1/2 inches above the clavicle. There is an immediate numbness of the skin below the wound and over the acromion and clavicle. The nerve most likely severed was the