Which nerve is associated with the adductor magnus?

The adductor magnus muscle is primarily innervated by the obturator nerve, which is responsible for the adduction of the thigh at the hip joint. This muscle also has a portion that receives innervation from the tibial division of the sciatic nerve, but the key association in terms of primary innervation is indeed with the obturator nerve.

The obturator nerve arises from the lumbar plexus and is specifically aimed at the medial compartment of the thigh, where the adductor muscles, including the adductor magnus, are located. Understanding this nerve's path and function is crucial for linking it to the muscles it innervates, especially those responsible for adduction movements.

The other options represent nerves that either innervate different muscles or are involved in entirely different functions. For instance, the musculocutaneous nerve primarily innervates muscles in the anterior compartment of the arm. The inferior gluteal nerve is associated with the gluteus maximus muscle in the gluteal region, while the radial nerve is primarily responsible for innervating the muscles of the posterior compartment of the arm and forearm. Thus, recognizing the specific roles and innervations of these nerves helps clarify why the obturator nerve is the correct answer