Answer:
The correct answer is YOU
Explanation:
In the following sentence the subject pronoun is YOU.
When you are speaking about your sister and yourself.
A subject talks about who performs the action, in this case the action is are speaking and this actions is performed by the subject pronoun YOU.
your sister is an exampleof an object, it means who receives the actions and yourself is a reflexive pronoun
The answer: C
Be the good girl you always have to be Conceal, don't feel, don't let them know Well, now they know
Thats what you need to know, Thats a personal question