Question

Scientists have recently found evidence that black holes—regions of space in which matter is so concentrated and the pull of gravity so powerful that nothing, not even light, can emerge from them—probably exist at the core of nearly all galaxies and the mass of each black hole is proportional to its host galaxy.

(A) exist at the core of nearly all galaxies and the mass of each black hole is proportional to

(B) exist at the core of nearly all galaxies and that the mass of each black hole is proportional to that of

(C) exist at the core of nearly all galaxies, and that the mass of each black hole is proportional to

(D) exists at the core of nearly all galaxies, and that the mass of each black hole is proportional to that of

(E) exists at the core of nearly all galaxies and the mass of each black hole is proportional to that of

Answer 1

Scientists have found evidence that black holes exist at the core of nearly all galaxies and their mass is proportional to that of their host galaxy. The presence of supermassive black holes in the centers of galaxies has been observed. These black holes have extremely high mass and are responsible for energetic phenomena.

Step-by-step explanation:

Scientists have recently found evidence that black holes exist at the core of nearly all galaxies and the mass of each black hole is proportional to that of its host galaxy.

This is supported by observations that show the presence of supermassive black holes in the centers of galaxies. For example, our own Galaxy has a supermassive black hole at its center with a mass equivalent to 4.6 million Suns. The existence of black holes is inferred based on the extreme concentrations of mass and the energetic phenomena observed in their vicinity.