A 65-year-old man is undergoing left radical neck dissection for squamous cell carcinoma. This procedure involves the dissection of all lymph nodes, as well as several vital nerves. After the surgery, the patient has trouble shrugging his shoulders. Damage to the nerve most likely causing this patient's new symptom can also manifest with the dysfunction of which other muscle?

1.Orbicularis oculi
2.Buccinator
3.Sternocleidomastoid
4.Rhomboid