Which of the following statements regarding the nerves of the neck is INCORRECT?

a. The vagus nerve courses through the neck in the carotid sheath and through the thorax posterior to the root of the lung.
b. The sympathetic trunk is located in the neck posterior to the carotid sheath.
c. The superior root of ansa cervicalis is derived from C1 and connects with the hypoglossal nerve.
d. The transverse cervical nerve and supraclavicular nerve are both derived from 2 and 3.