People acting in unison to bring about or resist social,political,and economic change are engaged in:

A) democratic government
B) economic development
C) collective action
D) collectivization
E) all of these choices

Collective action refers to a group of individuals who come together to achieve a common goal, whether it be bringing about social, political or economic change or resisting it. Democratic government and economic development are related concepts but do not encompass the idea of collective action. Similarly, collectivization refers to the organization of society and economy around the collective ownership and management of resources, which is a more specified term than collective action. Therefore, the best choice that describes the idea of people acting in unison to bring about or resist change is collective action.