An involuntary and nearly instantaneous movement in response to a stimulus is called:

Explanation

A reflex action is an automatic, involuntary, and rapid response to a stimulus, so this is the correct answer. A reflex is an automatic, involuntary, and rapid response to a stimulus that protects an organism from harm and aids survival. These responses occur through a reflex arc, a nerve pathway that bypasses the brain for instant reaction, though the signal is still sent to the brain for further processing or override. Examples include the sudden withdrawal from a hot surface, the pupil constricting in bright light, and the knee-jerk response to a tap.