Read this sentence from paragraph 1 of "YouTube: A World of Knowledge and Fun at Your Fingertips."
If the original YouTube founders had had a crystal ball, they might not have been so quick to sign on the dotted line!
The phrase "had a crystal ball" refers to the YouTube founders ___
A. believing in fortune-teller
B. owning something expensive
C. being dedicated and hardworking
D. knowing what happens in the future