Answer:
a. satorius
Step-by-step explanation:
The sartorius muscle is a two-joint muscle that moves both the hip and knee joints. Although anatomically considered a thigh extensor, its contraction actually causes a flexion of the hip joint. This is due to its location in the anterior (extensor) compartment of the thigh. Additionally, it is involved in abduction and external rotation of the hip joint.
In the knee joint, it forces an internal flexion and rotation. Flexion movement is the result of tendon insertion into the knee joint behind the flexor-extensor axis. When all five movements are performed simultaneously the legs cross in meditation position. Thus, the muscle is most easily palpable in this position.