Final answer:
Brian's task-focused and patient behavior, along with his preference for working in small groups, indicates that he is exhibiting an Amiable Style. Thus (option 3) is right answer.
Step-by-step explanation:
Brian's behavior aligns most closely with Option 3: Amiable Style. This behavioral style is characterized by a patient, team-oriented disposition, where individuals prefer cooperative efforts and working in smaller, more intimate groups.
An amiable personality is often contrasted with the expressive style, which is more outgoing and emotion-driven, and the driver style, which is more dominant and task-focused. Lastly, the analytical style is all about being detail-oriented and data-driven, which can sometimes lead to less patience when working in a team. Thus (option 3) is right answer.