Answer:
Option B: Resource mobilization theory.
Step-by-step explanation:
This theory looks at social movements as an organized effort, where success is directly related to the resources available, the way they are implemented, and the ability to gather financial support.
This was a very popular theory when it was first introduced back in the '70s, as was completely opposed to the common thought, that social movements were a disorganized group of people who find recruits among isolated individuals in society.