Answer:
The correct option is: a. lliopsoas m.
Explanation:
The iliopsoas muscle is a composite muscle in which the psoas muscle and the iliacus muscle are joined together. The main function of the iliopsoas muscle is the flexion of the thigh at the hip and it is also the strongest flexor of the hip. Therefore, the iliopsoas muscle is very vital for walking, running and standing.
Therefore, the iliopsoas muscle is the muscle that flexes the thigh at the hip.
