I think the answer is Hermia wishes to marry Lysander instead of Demetrius, her father's choice.
It would have to be: Make sure that you have clearly explained what happened, how it happened, and why.
"she" would be the pronoun.
You can rewrite this question as "She is your best friend?"
So in that case, "she" would be the subject.
In English, you just switch around "is" and the subject to make a question and make it sound Englishy
PS in Italian (and probably other languages) you would just say "She is your best friend?"
