Elizabeth tells her daughter taylor, "i will stop this nagging, which you find unpleasant, as soon as you clean your room today and continue to clean it in the future." this description indicates that elizabeth is trying to use

Answer: Operant conditioning.

Operant conditioning is a system that attempts to influence the strength of a behaviour by giving punishments or rewards. This can be divided in reinforcement, which is directed towards increasing the behaviour, or punishment, which tries to reduce it.

Both reinforcement and punishment can further be divided into positive (adding a stimulus) or negative (removing a stimulus).