Although the results are mixed, has often been used by teachers who are eager to instill order in an unruly classroom. a. a token economy b. programmed learning c. biofeedback training d. physical punishment

The correct answer is A.

A token economy is based on operant conditioning principles and consists on the reinforcement of a specific target behaviour. It can be applied both in scenarios with adults and children.

A token is an object that has no intrinsic value but that can be used as a reinforcer because it can be exchanged for privileges according to a set of pre-established rules. For example the token could be a voucher that allows the student who has stood in silence during the lesson to eat a snack in class.

c or d both can be the answer