Answer:
The rhyming scheme of this poem is "ABAAB".
Explanation:
The reason why its abaab is this:
In the first stanza for instance, there's 2 types of rhyming words, one that ends with -ood and -th. Lets say that the words that end with -ood is A and the words that end with -th is B. So applying this it would look like this.
Two roads diverged in a yellow wood, (A)
And sorry I could not travel both (B)
And be one traveler, long I stood (A)
And looked down one as far as I could (A)
To where it bent in the undergrowth; (B)
See the pattern you got there? That's called the rhyme scheme. Thus, meaning that the rhyme scheme is ABAAB.
It can also be applied to all the other stanzas. Lets take the second stanza for example.
Then took the other, as just as fair, (A)
And having perhaps the better claim, (B)
Because it was grassy and wanted wear; (A)
Though as for that the passing there (A)
Had worn them really about the same, (B)
You got the same results. Proving that the rhyme scheme is ABAAB.
Hope this helps!