Read the excerpt from chapter 10 of Animal Farm.

It was just after the sheep had returned, on a pleasant evening when the animals had finished work and were making their way back to the farm buildings, that the terrified neighing of a horse sounded from the yard. Startled, the animals stopped in their tracks. It was Clover's voice. She neighed again, and all the animals broke into a gallop and rushed into the yard. Then they saw what Clover had seen.

It was a pig walking on his hind legs.

Yes, it was Squealer. A little awkwardly, as though not quite used to supporting his considerable bulk in that position, but with perfect balance, he was strolling across the yard. And a moment later, out from the door of the farmhouse came a long file of pigs, all walking on their hind legs. Some did it better than others, one or two were even a trifle unsteady and looked as though they would have liked the support of a stick, but every one of them made his way right round the yard successfully. And finally there was a tremendous baying of dogs and a shrill crowing from the black cockerel, and out came Napoleon himself, majestically upright, casting haughty glances from side to side, and with his dogs gambolling round him.

How does Orwell use satire to achieve his purpose in this passage?

by having Clover neigh repeatedly to show a reversal in roles
by having the pigs walk awkwardly on two legs as an imitation of humans
by having the dogs frolic around Napoleon to make fun of the pigs
by having the animals return to the buildings to show a change in fortune