Why do you think Dave and Spitz (and later Sol-leks) punish Buck for his mistakes?

To give buck a good lesson.

Explanation:

Dave, Spitz and Sol-leks punish Buck for his mistakes in order to give him a good lesson and they are in-charge there. Dave, Spitz and Sol-leks are the dogs that punish buck because he is weak and helpless. Buck hate these dogs due to their behaviour with him. He hate Spitz due to mean nature, he laughed about Curly's death, attacked Buck many times, and stole hiding hole of the buck. Buck can't go against them due to their unity and strength.

the answern should be b, if it is the part where the mob has gathered

your answer is c) experiments with water vapor showed that elements combine in specific proportions.