give an account for the rise of class inequality in the novel 25marks

Here is something that adds further detail,

The Societal Tendency Toward Class Stratification

Animal Farm offers commentary on the development of class tyranny and the human tendency to maintain and reestablish class structures even in societies that allegedly stand for total equality. The novella illustrates how classes that are initially unified in the face of a common enemy, as the animals are against the humans, may become internally divided when that enemy is eliminated. The expulsion of Mr. Jones creates a power vacuum, and it is only so long before the next oppressor assumes totalitarian control. The natural division between intellectual and physical labor quickly comes to express itself as a new set of class divisions, with the “brainworkers” (as the pigs claim to be) using their superior intelligence to manipulate society to their own benefit. Orwell never clarifies in Animal Farm whether this negative state of affairs constitutes an inherent aspect of society or merely an outcome contingent on the integrity of a society’s intelligentsia. In either case, the novella points to the force of this tendency toward class stratification in many communities and the threat that it poses to democracy and freedom.