This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lower Extremity, Subject name: Anatomy
Tibialis posterior muscle is supplied by which nerve? 
Select and explain. 
A. Posterior tibial nerve, B. Deep peroneal nerve, C. Femoral nerve, D. Sural nerve
A: Posterior tibial nerve
Answer: A: Posterior tibial nerve 
Explanation: Ans A Posterior tibial nerveRef: Mac Glamry's Textbook of Foot and Ankle Surgery, pg. 196 Posterior tibial muscle is supplied by L5, S1 (posterior tibial nerve)# Action: Inversion of the foot at the ankle.# Test: The patient holds his foot in the inverted position while the examiner pushes outward toward eversion. Anterior tibial muscle is supplied by L4,5 (deep peroneal nerve)# Action: Dorsiflexion of the foot at the ankle.# Test: The patient dorsiflexes the foot and the examiner try to push the foot downward towards plantar extension.