Final answer:
The pig's footprints leading to the ruined windmill might imply a plot to sabotage the structure, suggesting betrayal and a quest for power in the story's context. Option 3 is correct.
Step-by-step explanation:
A more sinister explanation for the pig's footprints leading towards the ruined windmill could be that the pigs were trying to sabotage the windmill. This insinuation suggests a betrayal of the collective efforts and potentially the effecting of a power shift on the farm, aligning with the themes often explored in tragedies and political allegories in literature.
The pigs plotting to take over the farm is another possibility that indicates an internal power struggle and the existence of ulterior motives within animal society.