This doesn’t establish whether comedies and tragedies should be classified as satirical or romance literature. (A) fails to prove that if the major characters’ moral qualities change over time, then a work can’t be classified as satirical or romance literature.

Just because a work’s world changes during the course of action tells us nothing about whether that work can be classified as satirical or romance literature. (B) fails to prove that if characters’ moral qualities change, then the work can’t be classified as satire or romance.

This suggests that a character’s moral qualities change throughout a tragedy, but it tells us nothing about whether that tragedy can be classified as satire or romance. (C) fails to prove that a character’s morals changing means that a work can’t be classified as satire or romance.

Comedy and tragedy require that the moral qualities of major characters change during the course of the action. If characters’ moral qualities do not change in romance and satire, this guarantees the conclusion that comedy and tragedy cannot be classified as romance or satire.

We already know that comedy and tragedy require that the moral qualities of major characters change. The fact that minor characters’ morals also change tells us nothing about whether comedies and tragedies can be classified as romance or satire.