Answer:
C. by detailing the effects of the cold St. Petersburg weather
Step-by-step explanation:
Remember, the story begins by telling readers how the main character of the story, Akaky Akakievich Bashmachkin struggles to survive the effects of the cold St. Petersburg weather.
Akakievich is portrayed as an impoverished clerk, he struggles to save money in order to buy a new winter coat. Thus, the theme of the story ("The Overcoat") emerges further from here.