A laborer presents with complaints of weakness in his grip of the left hand. He is an electrician and for the past 5 months, he has noticed that his grip has steadily been getting weaker. He denies any abnormal sensation or injury to the arm or hand. The image of his left hand is shown. Further exam shows that he no sensory loss. Where is his pathology located with respect to the nerve?
A. Compression of the deep motor branch in the hand but before the branch to the hypothenar muscles has taken off
B. Compression of the deep motor branch in the hand after the branch to the hypothenar muscles has taken off
C. Involvement in the canal of Guyon with compression of both the deep motor branch and the superficial terminal sensory branch
D. Injury to the superficial terminal sensory branch distal to the canal of Guyon