Which of the following is a good summary of the passage above?

Question

     A black hole is a region of space-time from which nothing can escape, even light. This may sound strange, but it is possible. To see why this happens, imagine throwing a tennis ball into the air. The harder you throw the tennis ball, the faster it is traveling when it leaves your hand, and the higher the ball will go before turning back. If you throw it hard enough, it will never return because the gravitational pull will not be able to bring it back down.The velocity, or speed, the ball must have to escape is known as the escape velocity. Earth’s escape velocity is about 7 miles a second.

     As a body is crushed into a smaller and smaller volume, the gravitational pull increases, and the escape velocity gets bigger. Things have to be thrown harder and harder to escape. Eventually, a point is reached when even light, which travels at 186 thousand miles a second, is not traveling fast enough to escape. At this point, nothing can get out as nothing can travel faster than light.This is a black hole.

Answer 1

The third to last sentence is my educated guess because it has the passage condensed the best.