You can divide the top and bottom by 3 to make 11/12. 11 cannot be broken down anymore so that is the simplest form
I also agree that the answer is B: whom
in this sentence you are using the preposition + whom grammar structure. Whom is considered an object pronoun and is used when asking who will receive the action, which in this case, I believe is, baking those cookies. Hopefully this makes sense and good luck.
The answer is negative four because you must change two negatives into a positive