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
Muscle causing flexion of hip ? 
Select and explain. 
A. Biceps femoris, B. Psoas major, C. Gluteus maximus, D. TFL
B: Psoas major
Answer: B: Psoas major 
Explanation: Ans. is 'b' i.e., Psoas major