Answer:
C. Conflict
A theme is most commonly revealed through a text's treatment of conflict.
Step-by-step explanation:
A theme is the central idea or moral of the literary work. Themes are critical beliefs about life or human experiences in society. A literary work may have more than one themes, but usually there is one major theme and more minor ones.
Conflict is the struggle of characters against opposing forces e.g fear, hate, anger, fate, disease, society etc.
An author reveals the theme by presenting different characters' response in the face of internal and/or external conflicts. Authors also use many other literary devices and techniques such as plot, setting, symbols, mood to develop a theme. But it is mostly through text's treatment of conflicts.