The correct answer is C. Extrinsic motivation
Step-by-step explanation:
In psychology, motivation refers to the urge of doing a certain action or behaving in a certain way. This includes extrinsic and intrinsic motivation. Extrinsic motivation occurs if there is external regard, for example, a prize, money or a grade; on the other hand, internal motivation occurs if there is internal regard such as feeling better with oneself.
In the case of Brenda, she is motivated to study frequently to earn an A and in this way keep her grade point average high, this means the whole purpose of her actions and behaviors are grades which are external rewards, and therefore she is motivated by extrinsic motivation.