The statement that best explains how Boxer's response supports the author’s purpose in writing an allegory is:
Orwell uses Boxer's decision to avoid more carnage by working hard to show how the working class was manipulated.
Boxer's response reflects the tendency of the working class to blame themselves for the problems they face and to believe that working harder is the solution. This illustrates how those in power can manipulate the working class into accepting their suffering and continuing to labor under oppressive conditions, rather than recognizing and challenging the injustices they face.