Answer:
It would be answer A., AB AB AC AC
Explanation:
A rhyme scheme is essentially asking what lines rhyme. All four stanzas start with, it's winter, it's winter, it's wonderful winter, therefore they are all going to be the same letter and since it's the very first line, let's call it line A. Now the next line after that in the first stanza and in the second stanza both rhyme but after that they don't. So the next two lines of the first and second stanza are going to be b. So far, we have AB AB. After that though, the rhyme scheme changes. The two stanzas still start with it's winter, it's winter, it's wonderful winter so the A isn't going to change but the second line after line A does in both stanzas. C would be next, therefore the rhyme scheme is AB AB AC AC.
Hope this helps, I'm sorry for not explaining it better if it's a bit confusing.
