What did the pigs claim as their justification for changing the commandments?

The pigs justified changing the commandments primarily as a means to control the other animals. Throughout "Animal Farm," the pigs gradually manipulate the commandments to consolidate their power and maintain their dominance over the other animals on the farm. By altering the commandments, they create a narrative that allows them to claim authority and enforce their decisions without the animals being able to challenge them. This form of manipulation illustrates the theme of how those in power can distort truth to keep control over others. The other options, while they might seem relevant at first glance, do not encapsulate the pigs' primary motive of maintaining control over the populace, which is central to their governance and the overall message of the novella.