Final answer:
Chapter 2 of 'Animal Farm' is best summarized as the animals beginning to organize a rebellion against Mr. Jones, led by Napoleon and Snowball.
Step-by-step explanation:
The correct one-sentence summary for chapter 2 of Animal Farm by George Orwell is option (a): The animals begin to organize and plan a rebellion against their human owner, Mr. Jones, led by the pigs Napoleon and Snowball. This chapter sees the animals coalescing around the ideas of Animalism, planting the seeds for an impending uprising. Unlike options b, c, and d, this sentence accurately captures the essence of the chapter without delving into events that occur in subsequent chapters.