The correct answer is: [A] " It's" .
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(the choice with the apostrophe).
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" It's been a lovely time."
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Note: The word, "it's", {note: with the apostrophe}; is a contraction for "it is" or "it has". In this case, it stands for "it has". When you need to use "it is" or "it has", you either: 1) write out the "it is" or "it has" ; or, 2) write "it's" (that is, with the apostrophe).
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