Answer:
The correct answer is A) voltage-gated ion channels.
Step-by-step explanation:
Sensory receptors are specialized cells or organs that detect changes in the environment and convert them into electrical signals that can be transmitted to the central nervous system. In order to initiate nerve impulses, sensory receptors rely on the opening or closing of voltage-gated ion channels. These channels are specialized proteins that span the cell membrane and allow ions to flow in or out of the cell in response to changes in membrane potential. When a sensory receptor is stimulated by a stimulus, such as light, sound, or touch, it causes a change in membrane potential that triggers the opening or closing of voltage-gated ion channels, which in turn initiates the nerve impulse that travels to the central nervous system. Exteroceptors and interoceptors are types of sensory receptors that detect external and internal stimuli, respectively, but they do not directly initiate nerve impulses without the opening or closing of voltage-gated ion channels.