Answer:
C. problems in the social structure.
Step-by-step explanation:
Social structure refers to the way people run and operate the society within a certain region. This will include giving clear distinction between the roles of different social groups, their functions, and their purposes.
Social movements tend to occurred if a certain social group experienced a problem adapting to either their roles, functions, or purposes. Example of this would be the civil right's movement. That movement was held by the minorities citizens to protest about the roles and purposes that they have in US society . (at that time, they were treated as second class citizens with very few job opportunity and constant harassment)