Which nerve is responsible for the sensory supply to the posterior aspect of the leg?

The sural nerve is the correct answer because it specifically innervates the sensory regions of the posterior aspect of the leg. It is formed by contributions from both the tibial and common peroneal nerves, and it provides sensory innervation to the skin on the posterior side of the lower leg and the lateral aspect of the foot. This nerve plays a crucial role in the sensory perception of this area.

The tibial nerve, while it does contribute to the sural nerve and innervates muscles in the posterior compartment of the leg, is primarily responsible for motor functions and some sensory from the sole of the foot, not the posterior aspect of the leg itself. The peroneal nerve, on the other hand, primarily serves the anterolateral aspect of the leg and does not cover the posterior area. Lastly, the femoral nerve is mainly responsible for innervation in the anterior thigh and does not provide sensory supply to the posterior leg at all. Thus, the sural nerve is specifically the main sensory nerve for the posterior aspect, confirming its correctness as the answer.