What are the forces that struggle in the plot of a story?
the external and internal conflict
the good guy and the bad guy
the diction and the theme
the protagonist and antagonist

The right option is; the protagonist and antagonist

The protagonist and antagonist are the forces that struggle in the plot of a story.

The protagonist and antagonist are significant characters that cause conflict in a story. The protagonist is the main character of a story usually referred to as the lead, while the antagonist is the character that actively opposes the protagonist’s goals and is usually referred to as the villian. Stories can have more than one protagonists and antagonists, and active characters can also change between these roles in the story.