Answer:
The term that describes light, heat, and sound in the context of reflexes is "stimuli." Stimuli are changes in the environment that can trigger a response in an organism, including involuntary reflexes. For example, a bright light can cause a person's pupils to constrict reflexively, while a loud sound can cause a person to startle and jump. Similarly, exposure to heat can cause a reflexive withdrawal response, such as pulling away from a hot stove or touching a hot surface. Overall, stimuli play a crucial role in triggering reflexive responses in organisms and can include a wide range of sensory inputs, including light, heat, sound, touch, and more.