The correct answer is (b), Sartorius.
The sartorius is a long, thin muscle on the front of the thigh. It is the longest muscle in the human body, and it helps to flex the thigh and rotate the leg.
The biceps is a muscle in the upper arm that helps to flex the elbow. The triceps is a muscle in the upper arm that helps to extend the elbow. The rectus femoris is a muscle in the thigh that helps to extend the knee.
The sartorius is the longest muscle in the human body because it runs from the iliac crest of the pelvis to the medial tibial condyle of the tibia. It is a superficial muscle, meaning that it is located near the surface of the body. The sartorius is a multipennate muscle, meaning that it has multiple tendons that attach to the bone. This allows the sartorius to produce a lot of force.
The sartorius is important for a number of movements. It helps to flex the thigh at the hip joint, which is necessary for activities such as walking and running. It also helps to rotate the leg inward, which is necessary for activities such as kicking. The sartorius is also important for maintaining balance.
The sartorius is a relatively weak muscle, but it is very important for a number of movements. It is the longest muscle in the human body, and it is located on the front of the thigh. The sartorius helps to flex the thigh at the hip joint, rotate the leg inward, and maintain balance.