Usage of "even if, tense"

[Sitifan]

There ___ enough space to mention all the scholars on whose work I have drawn directly or indirectly, even if I had a complete record of my borrowings.
(A) is not (B) would not be
Which choice do you think is correct?
Thanks a lot for your reply.
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Thank you very much for your reply.

[Mister Micawber]

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For consistency in the conditional, B.
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Native English teacher at Mister Micawber's