When we say colloquialisms, these are words that are written informally in a literary work. Therefore, when writing an analytical essay, we should make sure that colloquialisms should be limited. It should be limited since an essay should be presented formally. The answer for this would be option D.
Your first option is correct.
EXPLANATION:
your first option is correct because this is a grammar question. When you use "an" you're using it in front of a vowel. The only sentence starting with a vowel is the first one. The others don't sound right when you use "an" in front of it instead of "a".
I hope I helped! :)
I think the answer is to convey how a literary work uniquely portrays a situation, event, or location
