Sentence Correction (SC) | Re: In August 2013, India was the first nation on record to declare

Hellohimanshu0123 ,

We hope this finds you well.

To answer your query, the use of "to be" in Option A is unidiomatic; Option A incorrectly uses the unidiomatic construction "declare X to be Y"; "declared/declared X,Y" and "declare/declared + that + clause" are the correct, idiomatic constructions.

We hope this helps.
All the best!
Experts' Global Team
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