Which movement is associated with the adductor longus muscle?

The adductor longus muscle primarily functions to adduct the thigh, which means it draws the thigh closer to the midline of the body. Additionally, this muscle can assist in laterally rotating the thigh when the hip is in certain positions, such as during flexion. This dual role in both adduction and lateral rotation is crucial for various movements in activities such as walking, running, and changing direction.

While the other movements listed may involve different muscles, they do not accurately describe the specific role of the adductor longus. For example, flexing the hip is primarily the function of muscles like the iliopsoas, while plantar flexion of the foot is associated with muscles in the calf, such as the gastrocnemius and soleus. The flexion of the leg involves muscles around the knee joint, particularly the hamstrings. Therefore, option B correctly identifies the movement specifically associated with the adductor longus muscle.