Correct sequence of reflex are is
(1) Receptor → Motor Neuron → Sensory Neuron → Effector organ → Relay Neuron
(2) Receptor → Sensory Neuron → Motor Neuron → Effector organ → Relay Neuron
(3) Receptor → Sensory Neuron → Motor Neuron → Relay Neuron → Effector organ
(4) Receptor → Sensory Neuron → Relay Neuron → Motor Neuron → Effector organ