Answer:
That would be A
Explanation:
Adding "in" to the word substantial would result in a word meaning the opposite.
An interior narrative, also called interior monologue, is a narrative technique that is used to depict a character's thoughts, feelings and impressions that goes through the minds of these protagonists, in a form of a narrative. This is usually used in dramatic and nondramatic fiction.
A. because dramatic irony is when the term is understood my the audience not the actors in a play