Answer:
Reward system
Step-by-step explanation:
Because Jackie wants her dog to bring her mail each time it's dropped, she makes him go to the mail slot and each time the dog returns she gives him treats. This is an example of reward system.
Reward system is simply the concept of gifting someone a prize on completion of a task. This is to make that person know that if he does or performs a task to a certain level, he gets rewarded. This can be viewed in relationships of some parents and their children.
The parent may tell a child that for each good grade he gets in school, he'll be given more pocket money to meet his needs. This child is eager to get good grades so his pocket money can be increased.
This is the same concept Jackie is using for her dog. If the dog eventually discovers that each time he brings in her mail, he's given a treat, he would be eager to bring it to her as soon as possible.