At First,it Was Thought That Nothing Could Ever Escape from a Black

At first,it was thought that nothing could ever escape from a black hole,yet astronomers are now locating black hole candidates by the X-rays they emit.Do they really see X-rays coming from a black hole?

A) The X-rays come from highly compressed matter in the accretion disk outside the event horizon of the black hole.
B) The black hole modifies spacetime around it so much that particles and X-rays are created in the vacuum itself,just outside the event horizon.
C) The X-rays are produced by vibrations of the black hole itself,and therefore they come from the event horizon,and not from inside the black hole.
D) X-rays are neither light nor matter and therefore can escape from inside the black hole.