19. Little Red Riding Hood is delivering waffles to three grannies. She starts with a basket full of waffles. Just before she enters the house of each granny, the Big Bad Wolf eats half of the waffles in her basket. She delivers the same number of waffles to each granny. When she leaves the third granny's house, she has no waffles left. Which of the following numbers definitely divides the number of waffles she started with?
A 4
B 5
C 6
D 7
E 9