One of the following gives the correct sequence of the components in a reflex arc. This is:
A. Receptors `rarr` Muscle `rarr` Sensory neuron `rarr` Motor neuron `rarr` Spinal cord
B. Receptors `rarr` Motor neuron `rarr` Spinal cord `rarr` Sensory neuron `rarr` Muscle
C. Receptors `rarr` Spinal cord `rarr` Sensory neuron `rarr` Motor neuron `rarr` Muscle
D. Receptors `rarr` Sensory neuron `rarr` Spinal cord `rarr` Motor neuron `rarr` Muscle
