The correct option is B Dopamine
Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called as, dopamine. Symptoms begin gradually, often on one side of the body. Later they affect both sides. They include - trembling of hands, arms, legs, jaw and face, the stiffness of the arms, legs and trunk, slowness of movement, poor balance and coordination.