We say words rhyme when their final sounds are the same. For example: feel - peel; cat - bat.
<u>To find the rhyme scheme of a poem, we must attribute letters to the final word of each line. The first final word is always A. Any words that rhyme with it will also be A. The next word with a different final sound will be B. The words that sound like it will also be B. The next different one will be C, and so on.</u>
With that in mind, let's look at each final word from the excerpt:
All the other choices are negative or portray owning a pet in a negative light. C is the only answer choice that argues that your life will improve/become more positive by owning a pet.