Answer:
The answer to your question would be option B, the importance of social justice.
Step-by-step explanation:
The topic of social justice can be found throughout the novel To Kill a Mockingbird. For example the author of the book describes several social justice issues that affect a number of people in the novel, such as racism.
Through the book, certain characters such as Scout, confront the difficult truths about racism, and at the end of a novel, when she mentions killing a mockingbird, it can be inferred that she refers to the theme of social justice as, through her journey, Scout has learnt that while courts are a source of justice, there are also other ways of achieving justice outside of it.