The foreman constantly nags the bricklayers to work faster. When the wall is finished, he stops nagging. This is an example of reinforcement. negative selective singular positive

The answer is negative reinforcement.

Explanation:

In operant conditioning, negative reinforcement occurs when an unpleasant stimulus is removed after a behaviour is completed. In the example, the nagging will stop once the job has been done.

Negative reinforcement has been proved to be more effective than positive reinforcement (rewards).