Given below are four jumbled sentences. Out of the given options pick the one that gives their correct order.
A. But when their short racing careers are over, greyhounds are adopted as household pets.
B. Greyhound racing is a popular spectator sport in the United States.
C. They worry that the greyhounds would need a large space to run to get sufficient exercise.
D. Unfortunately, many people hesitate to adopt a retired racing greyhound as a pet.