IN: Which person is it?
The bird ate the pie and it was ruined.
OUT: the pie

IN: Which person is she?
Misty was replaced by May because she had to go back home.
OUT: Misty

IN: Which person is they?
The jocks did not like the nerds because they were bullies.
OUT: The jocks

IN: Which person is she?
Jessica did not like Selma cutting her hair short, but she ended up loving her new style.
OUT:
Jessica