A patient presents with numbness and weakness of the left hand. Examination reveals decreased pinprick sensation in the first three and a half fingers and thenar eminence along with weakness of thumb flexion and abduction. Nerve conduction studies will most likely detect a problem at which of the following sites?
A. median nerve at the carpal tunnel
B. median nerve in the forearm
C. radial nerve in the arm
D. ulnar nerve at the elbow
E. ulnar nerve at the wrist
