The method that will MOST likely assist Martin in conjuring a background for his story is plotting the location. This is because a well-defined setting can significantly enhance a story, influencing the plot, character development, and overall atmosphere. By determining where the story takes place—both in a physical sense (geographical location) and a historical or cultural sense—Martin can create a more immersive and believable world for his readers.
Explanation of Your Incorrect Choice: You chose story mapping, which typically focuses on outlining the structure of the plot, character arcs, and key events rather than the background or setting of the story. While story mapping is a useful tool for organizing thoughts about a narrative's progression, it may not provide the depth of context that specifically plotting the location can offer.
Example of What Is Right: For example, if Martin's novel is set in a dystopian future, he might start by plotting the location of his story. He could define the characteristics of this world—such as a city in ruins, a society that has collapsed, or a hidden underground civilization. He could consider the geographical features, climate, and how these affect the characters and their daily lives. This foundational work on the setting would allow him to generate ideas for the plot, character motivations, and the overall themes of his novel, making it a vital step in his writing process.