The answer is "D" my dude. Hope this help :D
I'm not sure what the lesson is, but the answer that makes sense the most is number. Number because most lessons in subject-verb agreement concerns the singularity and plurality of the subject at hand
Noun because it is an object( person place or thing
Your answer would be B. the author's name is properly capitalized, the punctuation is correct, and when titling a short story- the title should be in quotation marks as shown in example B- "The Gift of the Magi"