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.
Answer:
okay so you are going to want to write a poem and make it ryhme and then you want to put simles in there and any other figurative language in there and then follow the structure of the poem and then have discriptive words in there that go with the poem
Explanation:
The main idea was that Mordred knew that he was dying so he took the opportunity to kill King Arthur