One Feature That Distinguishes a Black Hole from All Other

Multiple Choice

One feature that distinguishes a black hole from all other objects in the universe is that

A) the escape velocity from inside a black hole is greater than the speed of light.
B) a black hole emits large quantities of X-rays.
C) a black hole exceeds 3 solar masses.
D) the shape of the gravitational field of a black hole is different from that of an ordinary massive object, even at large distances from it.