The saphenous nerve is responsible for sensory function in which region?

The saphenous nerve primarily provides sensory innervation to the skin on the medial aspect of the leg and foot. It is a branch of the femoral nerve and travels down the leg, where it supplies sensation to the skin over the medial side of the leg, extending down to the medial side of the ankle and foot. This makes the sensory function of the saphenous nerve specifically related to the leg, which is why the correct answer is the leg.

In contrast, the other areas listed—fingers, foot, and neck—are innervated by different nerves. Sensory functions in the fingers are primarily managed by the median, ulnar, and radial nerves, while the foot has sensory innervation from branches of the tibial and deep peroneal nerves. The neck has its own distinct set of nerves, including the cervical nerves, which provide sensory and motor functions to that region. Therefore, the specificity of the saphenous nerve's sensory role relates directly to the leg, making this the accurate choice.