The correct answer is EXTENDED METAPHOR.
Extended metaphor refers to a comparison between two things that are not alike, which continues throughout a series of sentences in a paragraph or in lines of poem. It is also called sustained metaphor and authors usually use it in order to create a clear comparison between two things.
In the novel, after Mary Shelley's mother died her dad Godwin took care of her, this connects to the novel. When Victor Frankenstein's mother died from disease, his dad took care of him. In both situations, the mother died when they are young and the dad took care of him/her.
Answer:
The Open Window by Saki the author uses a third-person omniscient point of view.