Jill and her lab partners exposed a muscle from a donor that was medially attached to the thoracolumbar fascia and whose fibers coursed superficially to attach to the arm. The superficial part of its...

Jill and her lab partners exposed a muscle from a donor that was medially attached to the thoracolumbar fascia and whose fibers coursed superficially to attach to the arm. The superficial part of its medial attachment was partially covered by the trapezius muscle. What muscle(s) did they expose?

A. The latissimus dorsi

B. The rhomboid muscles

C. The levator scapule

D. The deltoid