Answer:
C. to indicate actors' onstage movements, positions, and tone
Step-by-step explanation:
The stage directions are instructions from the author of the play of how the actors should act in certain parts of the work. For this reason, the author places indications that must be followed about the movements, positions and the type of emotion that the actors must transmit when interpreting that character at a certain moment in the play, thus allowing the story to be established as the author imagined.