Answer:
"None of your business."
Explanation:
Most people don't want to state why they are sad because it feels like they are reliving the moment, and they start feeling worse. The first step towards feeling better is letting go, and by repeating the same moment, you think of all the things you could've done to avoid feeling that way. Unless they are willing to help, don't give them unnecessary information. Let go, and breathe.
(dibs on brainliest >:P )
