Answer:
Instrumental learning
Explanation:
Associative learning is a form of learning which is performed when two or more events or stimuli controls the learning behaviour. The instrumental learning is a type of learning in which the learning process is associated with the consequence or result of the action.
In the given question, the mouse learns how to step on the lever as a result of the received food in the form of reward or he learned because he received the treatment, therefore, this act of learning will be considered the instrumental learning.
Thus, Instrumental learning is correct.