Answer: a. supported by intrinsic motivation.
Explanation:
If paying above-market wages can result in or be supported by intrinsic motivation, profits may be improved because the workers will work harder than they normally would have.
Intrinsic motivation refers to refers to the part of person's drive that is inspired by the internal rewards that they hope to gain which means that it comes from the person themselves. If workers want to work hard, profits will come because productivity will be higher.