SC - Though research remains to be done into the reasons

[naftalih93]

Though research remains to be done into the reasons why the Civil War was triggered, scholars do not regard slavery to be the sole cause.

A Though research remains to be done into the reasons why the Civil War was triggered, scholars do not regard slavery to be the sole cause.
B Though research remains to be done into what triggered the Civil War, scholars do not regard slavery as the sole cause.
C Though the reasons that triggered the Civil War remain to be researched, slavery is not regarded by scholars to be the sole cause.
D Despite research remaining into the reasons why the Civil War was triggered, scholars do not regard slavery as the sole cause.
E Scholars do not regard slavery as the sole cause of the Civil War, though the reasons for it being triggered remain to be researched.

This is from the Manhattan SC bank question 23\25

OA B

I dont understand how remains to be done into is grammatically correct.

Also, research remains to be done into sounds very awkward. Is there really no problem with this phrasing? "the research remains to be DONE INTO" something?

Isnt this better?:

Research into the cause of X remains to be done.

Thanks for your insight

[Sage Pearce-Higgins]

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