Is this considered plagiarism?

Question

Original passage: A letter of thanks is a courteous acknowledgment of a gift or of something that was done for you.
Another passage: A thank you note is a polite acknowledgment of a present or something nice someone did for you.
Please also explain why is it plagiarism or not.

Answer 1

No, it's not plagiarism.

Answer 2

Yes it is

Answer 3

No I’m the real @Ms. Sue