The system that is included in the kinetic chain is the nervous system. The kinetic chain refers to the chain of movements that occur in the human body during various physical activities. This chain involves the coordination and interaction of multiple body structures, such as bones, muscles, and joints, to produce movement. The nervous system plays a vital role in this process as it is responsible for sending and receiving signals that initiate and control muscle contractions. These signals travel from the brain, through the spinal cord, and into the peripheral nerves to reach the muscles involved in the movement. Therefore, the correct answer is option a, the nervous system.
