Answer:
Expectancy theory
Explanation:
We are told that as long as he receives C grades or better, he maintains his current grade point average.
This means that;
There is a large tendency for him to work just hard enough to earn a c grade.
This depicts vrooms expectancy theory of motivation which is defined as a theory whereby a person or persons will act in a particular way just for the sake of what they will gain from exhibiting that particular selected behavior instead of others.