Final answer:
April is using her reward power by acknowledging her team's accomplishment with recognition, which serves as a non-material reward for their achievement in earning an industry award.
Step-by-step explanation:
April is utilizing her reward power when she congratulates her staff and announces their success via a company-wide email. Reward power is based on the ability to give rewards to others for their performance or behavior. In this case, April is giving recognition, which is a form of intangible reward, to her team for receiving an industry award for their project.