Final answer:
The main theme of the short story is that seeing cruelty and injustice inflicted on another person has the ability to change someone.
Step-by-step explanation:
The main theme of the short story can be described as C. Seeing cruelty and injustice inflicted on another person has the ability to change someone.
In the story, the reader witnesses how the protagonist's perspective and behavior change as a result of witnessing the cruelty and injustice inflicted on another person.
This theme highlights the transformative power of empathy and the impact that witnessing injustice can have on an individual.