The statement "Wolves are similar to humans in their social organization" can be supported by the following points from your list:
A. "A wolf pack may have as many as twenty wolves." - This illustrates that wolves live in social groups similar to human communities.
C. "Most packs are led by an adult male and adult female." - This shows a hierarchical structure in wolf packs that is somewhat analogous to human social organizations, where there are often leaders and followers.
B. "By three weeks of age, wolf pups are able to play." - While this point emphasizes development and social interaction among wolf pups, it is less directly related to social organization.
D. "The average size of a wolf litter is around four pups." - This fact provides information about reproduction but does not directly relate to social organization.
Based on this analysis, points A and C are the most relevant to the idea of wolves having a social organization similar to humans.