Concept:Motor neurons carry signals from the central nervous system directly to effectors such as muscles and glands.
Explanation:Effectors are the organs that produce a response, like muscles or glands.
The cells that transmit messages to these effectors are motor neurons.
Motor neurons are also called efferent neurons because they send impulses outward.
They possess long axons and short dendrites, which help deliver signals over long distances.
Sensory neurons work in the opposite direction, carrying impulses from sense organs to the central nervous system.
Relay neurons are found in the brain and spinal cord, connecting sensory neurons to motor neurons.
Hair cells are special sensory cells in the inner ear that detect sound and balance, not effectors.
Therefore, when the question asks which cells transmit messages to the effectors, the answer is motor neurons.
Answer:A. motor neurons