A man complains of loss of sensation in his little and ring finger. Which nerve is most likely to be involved?

The key is B. Ulner nerve. [Compression of ulner nerve at the elbow, known as cubital tunnel syndrome, causes numbness in the 5th (pinky) finger, along the half (lengthwise) of the 4th (ring) finger closest to the 5th finger, and the back half of the hand over the 5th finger].