Which of the Following Locations in Our Universe Has Been

Multiple Choice

Which of the following locations in our universe has been suggested as the site of a supermassive black hole?

A) The center of the Ring Nebula in Lyra,an old star
B) The center of the Crab Nebula,an old supernova remnant
C) The center of the universe,as defined by the universal expansion of the observable universe
D) The center of our Galaxy