A reflex action may defined as an instantaneous and involuntary action in response to an environmental stimulus. The reflex arcs (neural pathways) are responsible for the functioning of reflex actions as they act on impulses before these impulses reach the brain.
Corneal reflex or blink reflex is an example of reflex action that involves blinking of eyelids due to corneal stimulation, such as by a foreign body, intense light, or bu touching) to protect eye.
Thus, the correct answer is option B). 'blinking when light is flashed in the eyes.'
If you are conducting a study on the health of people who have been exposed vs not exposed, the method you should use to obtain data would be an observational study because it involves the pre-existing condition of the subjects.
