Final answer:
A 'chapter' in motorcycle gangs is equivalent to a 'set' in street gangs, referring to the organizational subdivisions within the gang that hold specific territories and are structured with their own local leadership.
The correct option is b.
Step-by-step explanation:
A chapter in motorcycle gangs is the same as a "set" in street gangs. The term 'chapter' refers to the organizational structure within motorcycle clubs, similar to how street gangs organize themselves into sets for the purpose of maintaining order and establishing a system of leadership and membership within specific geographic territories or areas of influence. It is an integral part of a club's identity and functions similarly to a branch or division of the larger club, with its own local leaders and members who are part of the overarching national or international motorcycle club.