Final answer:
A double story with elements of Realistic or Naturalistic fiction can be classified as a a. Mystery Novel with elements of the Gothic tale genre.
Step-by-step explanation:
The representation of elements of Realistic or Naturalistic fiction in either (or both) stories can be analyzed through their genres. A double story, where one takes place on the surface and another under the surface, can be classified as a a. Mystery Novel.
Mystery novels often represent elements of Realistic fiction by focusing on solving a crime or uncovering hidden truths. Additionally, if the story includes supernatural or dream-like events, it may also have elements of the Gothic tale genre, which is considered a subgenre of Mystery and can be associated with Naturalistic fiction.