Fact 1: Ablack hole is formed by a high-mass star collapses.

Fact 2: Essentially, a black hole is a gravity drain.

Given the two facts above, answer the question "What is formed by a high-mass star collapses?" with the following options: 
- grave error
 - an object
 - a gravity drain
 - mass grave
 - deoxyribonucleic acid
 - Physical weathering
 - gravity depletion
 - hydrogen and oxygen


 

   a gravity drain      