Which of the Following Is the BEST Example of a Community-Of-Learners

Which of the following is the BEST example of a community-of-learners approach in the classroom?

A) Mr. Addison, who assigns each child a different project topic and has them present their topics in small groups.
B) Mrs. Barnett, who has a local farmer come in and explain crop harvesting to students.
C) Mr. Chisholm, who has students work in small rotating groups on their project about the environment.
D) Mrs. Dixon, who has her class do group projects on different communities in their city.