Which of the following is an example of a neutral stimulus becoming a conditioned stimulus?

The correct answer highlights a fundamental concept in classical conditioning, which was originally developed by Ivan Pavlov. A neutral stimulus is initially something that does not elicit a specific response on its own. However, through the process of association, it can become a conditioned stimulus.

In this case, when a light turns on before food is presented, it is initially a neutral stimulus that does not trigger any response related to hunger or salivation. However, after repeated pairings of the light with the food, the light itself starts to evoke a response, specifically salivation, even when food is not presented. This transformation occurs because the light becomes associated directly with the presentation of food, thus converting it into a conditioned stimulus.

The other options refer to different psychological concepts or processes that do not involve the transition from a neutral stimulus to a conditioned stimulus. Salivating at the sight of food is an example of an unconditioned response to an unconditioned stimulus (food itself). Studying before an exam is related to preparation and learning behavior, while receiving praise after good behavior pertains to operant conditioning, which involves reinforcement rather than the conditioning of stimuli.