In order to get her third grade students to memorize the states of the USA, Mrs. Salmond gives the students stickers for each daily quiz on the states. After earning 5 stickers, a student gets to pick a prize out of the treasure box. Mrs. Salmond is using (a) to modify the children's behaviors.

Token economy

Explanation:

Token economy is a use of positive encouragement to establish a positive change in a specific behavior of a target group of people.

Token economy are used by teachers in a classroom to build up and maintain the right behaviour and standard in a classroom. It is a way to reward students for excellent performances and good behaviors.

Examples of Tokens that can be used are gold stars, stickers which can placed on the student's desk or given to the student directly.