Answer: The correct answer is A: Respondent Extinction
Explanation: A respondent extinction is the process that ocurrs when a previously conditioned stimulus (In this case the Flashing light) is presented while witholding the unconditioned stimulus (In this case, the loud noise) so it stops eliciting the conditioned response (In this case, the startle reflex).
The correct answer is A: the process in which a conditioned stimulus is no longer able to elicit a conditioned response is referred to as respondent extinction.