Answer: C. Abcc
A rhyme scheme is a pattern of rhymes at the end of a poem or song. Most of the time, the rhyme scheme is described by assigning letters to each line. The lines that rhyme with each other share a letter, and the letters are assigned in alphabetical order. In this case, the word "red" and "blue" do not rhyme. Therefore, they are assigned the letters "a" and "b" respectively. The words "yellow" and "mellow," on the other hand, rhyme, and therefore they are given the letter "c."