Which one of the following depicts the correct circuit of a reflex arc?

• A. Effector→sensory neuron→spinal cord→motor neuron-receptor
• B. Receptor→sensory neuron→spinal cord→motor neuron→effector
• C. Receptor→sensory neuron→brain→motor neuron→effector
• D. Sensory neuron→receptor→brain→effector→motor neuron