A 22-year-old female student was found to have an anterior mediastinal mass on a chest x-ray for a persistent cough. What finding is true regarding the thymus gland?
A
It is located in the posterior mediastinum.
B
It arises from the first branchial arch.
C
It controls calcium metabolism.
D
It is usually excised through an incision along the anterior branch of the sternomastoid.