Answer: A. in the cast of characters at the beginning of the play.
Explanation:
A list of all the characters in a play can be found in the cast of characters at the beginning of the play.
The cast of characters at the beginning of the play contains the list of characters and the role played by each so that the readers can have a better understanding of the play.
If you are really feeling this way, you should give it to your teacher, and if you want you can discuss more if your are comfortable or to someone else who can help you.