Maggie needs to paint 4 rooms of the same size in her house. It takes her 5 hours to paint each room. The number of minutes it takes Maggie to paint rooms is a function of the number of rooms that she paints. Select the domain of this function.
A. {0, 1, 2, 3, 4}
B. {0, 1, 2, 3, 4, 5}
C. {0, 5, 10, 15, 20}
D. {0, 4, 8, 12, 16, 20}