Answer:
C. Character.
Step-by-step explanation:
The short story of "The Sniper" by Liam O'Flaherty tells the story of a Republican sniper in a war of bullets against an enemy sniper who later turns out to be his own brother.
The excerpt in the question is from the initial paragraph of the story which gives a detailed description of the Republican sniper, our protagonist. The details such as "the face of a student, thin and ascetic, but his eyes had the cold gleam of the fanatic" or "eyes of a man who is used to looking at death" gave the shape of the character. We also know about his profession with the inclusion of the detail "rifle and over his shoulders was slung a pair of field glasses". All these details of the second paragraph of the short story gave us the character of the sniper.