In this passage from "Animal Farm", by George Orwell, the detail that bests supports the idea that oppressive leaders use propaganda to achieve their goals is option B “Snowball and Napoleon sent out flights of pigeons . . . to mingle with the animals on neighbouring farms . . . and teach them the tune of ‘Beasts of England.’”
Propaganda is the spreading of rumors and true, false or incomplete information to influence public opinion. In this passage we learn that the enemy is Jones. Snowball, Napoleon, and the pigs are brain-workers who look after the welfare of the farm. They are the obvious leaders, because they are smart, and so they are entitled to eat the best food and drink milk. Propaganda together with the unwillingness to question authority makes the oppressed to obey without thinking. So they send out flights of pidgeons to mingle with the animals on neighboring farms to learn the tune of "Beasts of England", a way to use propaganda to achieve their goals.
