This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
The involvement of the L5 Nerve Root can affect all of the below movements, except: 
Select and explain. 
A. Adduction of the Thigh, B. Flexion of the Knee, C. Extension of the Great Toe, D. Extension of the Knee
A: Adduction of the Thigh
Answer: A: Adduction of the Thigh 
Explanation: The L4 nerve root is involved in the adduction of the hip, extension of the knee and dorsiflexion of the ankle. Thigh adduction is not mediated the L5 nerve root. The muscles of thigh adduction are supplied by the Obturator Nerve. Obturator nerve (L2 to L4 anterior divisions) adducts and medially rotates the thigh. Ref: Peripheral Nerve Injuries in the Athlete, 2003 By Joseph H. Feinberg and Neil I. Spielholz, Page 214; In a Page Neurology, By Jon Brillman, Scott Kahan, 2005 Blackwell Publishing, Page 155; Color atlas of human anatomy:Locomotor system, By Werner Platzer, Edition 2008, Page 240.