At a home improvement store, customers can rent a small cargo truck to transport any large items they purchase. The store charges $20 as a rental fee plus $7.50 per hour to rent the truck. Which equation best represents the situation?
A. y= 7.5x - 20
B. Y= 7.5x +20
C. Y= 20x - 7.5
D. Y= 20x + 7.5