Let me also join the fray; between A and D.
If the first sentence says “than ever before”
, then this is indeed a deep question and my reasoning would be this for voting A.
You can see a subtle comparison in the sentence: -The financial crash of October 1987 demonstrated that the world’s capital markets are integrated ‘more closely than ever before’
– This comparison as signified by the adverb 'more closely’
pertains to the integration in 1987 to the integration any time before. In other words, the integration was there before 1987 and was therefore in 1987 and only the depth differed. Therefore, it will not be ideal to separate more closely
from than ever before
. D faults on this important implied meaning of the text by allowing the intrusion of the verb ‘integrated’
If on the contrary, the first choice says ‘than never before’
, then this is simple test of maintaining the relative pronoun //ism and the answer will be obviously D.
I do not wish to analyze how the original differs from this post, especially after the poster has said that he has made some changes. I am trying to look at the given topic per se and go about it. For all that b14kumar’s version is much better IMO
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