Final answer:
The correct answer is option b. Sheep.
Step-by-step explanation:
The group of animals in George Orwell's novel “Animal Farm” that become brainwashed followers of Napoleon are the sheep. Napoleon, a pig in the story, slowly cultivates the sheep's blind loyalty to use them as a tool of propaganda, often having them break into choruses of “Four legs good, two legs bad” to drown out dissenting opinions and debate.
This reflects the larger themes of the book, including how totalitarian regimes can manipulate the masses.