What is the meaning of the phrase “mulled the idea around in his mind” from the fifth paragraph? A. worried constantly about the idea
B. made a decision about the idea
C. carefully considered the idea
D. felt unhappy about the idea

The answer is C (carefully considered the idea)

Explanation:

Definition of wrap one's mind around: to find a way to understand or accept (something)

Example: I just couldn't wrap my mind around what had happened.

given the fact that the question is about the detail that best support the idea that oppressive leaders use   propaganda to achieve thir goals,   the first option does not refer to any kind of propaganda, since it only tells about that the milk and the windfall apple should be reserved for the pigs. in the second option, that is, "snowball and napoleon sent out flights of pigeons whose instructions were to mingle with the animals on the neighbouring farms, tell them the story of the rebellion, and teach them the tune of "beasts of england". it can be identified that the oppressors make use of the propaganda, which is represented by the pigeons, and the information they have to tell other animals about what was happening in the farm in order to get their objectives. for that reason, the right answer is the second option, taking into account that the third option do not refer to propaganda since it only talks about that they did not want jones back. and, finally, the last option refers to the result of the given news, but it does not mean about the propaganda they used to achieve their goals.