Why does Orwell use a farm specifically as an allegory in Animal Farm?

wanted
to write a story in which there were many different kinds of animals representing many different
kinds of people. He really didn't have much of a choice for his setting because a farm was about
the only place (except for a zoo or possibly a jungle) in which he could have a whole lot of
different animals living together. A farm was also a place where many of the animals worked in
one way or another, and his story was intended to have animals substituting for workers. It
would have been possible to have a story set in a zoo, with all the animals revolting and
breaking out of their cages; but most of these were wild animals and the author would have a
hard time showing them suddenly beoming cooperative and industrious. The pigs would have gotten
eaten up rather quickly. On a farm he wouldn't have to show lions, tigers, leopards, bears, and
snakes. Same problem with a jungle. There at least the animals are relatively free already and
wouldn't have to revolt. There was really no choice for Orwell but to set his story on a
farm.