Caesar the ape found out the door code by watching Morris, so he was able to escape.

Who is "he" in this prior sentence?
Caesar the ape
The environmentalists were angry at the corporation because they saw them polluting the creek.

Who is "they" in this prior sentence?
The environmentalists
The grandmother threw her granddaughter to her death because she felt jealous.

Who is "she" in this prior sentence?

The grandmother