Which words list the correct order of activated neurons in a reflex arc?

Here is the correct order of activated in a reflex arc.
(1) Receptor: where stimulus action is.
(2) Sensory Neuron: responisble of transmitting afferent impulses to the central nervous system.
(3) Integration Center: Sensory impulse to motor impulse; Direct (monosynaptic) or polysynaptic region in CNS.
(4) Motor Neuron: Efferent impulses from integration center to effector.
(5) Effector: Muscle fiber or gland cell that responds to the efferent impulses. 

Answer two atoms of oxygen;