Final answer:
Carbund, being a structured professional fraternity with established membership criteria and activities, is an example of a formal group.
Step-by-step explanation:
Given the information that Carbund is a professional medical fraternity with specific criteria for membership and outlined activities for its members, Carbund is best described as an example of a formal group. Formal groups are characterized by structure, specified roles, and established procedures for functioning. As a fraternity that operates within a professional field, Carbund fits this description, as opposed to an informal group, which would have less structure and defined roles. Additionally, Carbund is not an outgroup, as its members likely share a sense of belonging and identity within the fraternity, and it is not a dissociative group, which would imply rejection of certain norms or values.