Final answer:
The question deals with a storyline that involves characters facing complex situations such as affairs and tragic events, which is part of English literature analysis typically taught at the high school level.
Step-by-step explanation:
The subject of this question revolves around a narrative involving characters such as a lab technician, Sam Sheppard, and incidents of an affair. This falls under the category of English, specifically within the segment of literature analysis. The details provided from passages about McTeague and Trina, as well as the veiled hints and tragic news delivered to a character regarding a railroad disaster, pertain to literature and the analysis or discussion of story elements, character behavior, and plot development. The grade level is most likely high school, where students often explore themes in literature, character motivations, and the repercussions of actions represented in fictional narratives.