Clear B.
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
toThe key noun in the sentence is the plural ‘black holes’ so the verb that corresponds to black holes must be plural. What is that verb? ‘exist’ (ignore all of the content that comes in between the hyphens).
Now, ‘exist’ is correct, but the issue remaining is that the sentence conveys this idea that the mass of each black hole is proportional to its galaxy. The real intent here is to say that the mass of the black hole is proportional to the mass of its galaxy.
Out.
(B) exist at the core of nearly all galaxies and that the mass of each black hole is proportional to that of
Correct. The demonstrative pronoun ‘that of’ makes it clear that the mass of the black hole is proportional to the mass of its galaxy.
(C) exist at the core of nearly all galaxies, and that the mass of each black hole is proportional
toSame issue as A)
(D)
exists at the core of nearly all galaxies, and that the mass of each black hole is proportional to that of
‘exists’ is singular’. OUT.
(E)
exists at the core of nearly all galaxies and the mass of each black hole is proportional to that of
‘exists’ is singular. OUT.
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