The correct answer is a Reeve. This is because a reeve is a Manager someone’s estate or farm.
Hope this helps.....
Your answer should be WHO.
Think of it like this: You wouldn't say "The boy it (a variant of 'which')", because it simply just sounds odd. Instead, you're wired to think "The boy, he (an unknown name, so it would be 'who')".
What’s this ? I don’t understand your question.