When Do We Expect Special-Interest Groups to Form

When do we expect special-interest groups to form?

A) when the benefits are spread out over many and the costs are concentrated on a few citizens
B) when the costs of a project are spread out among all taxpayers while the benefits are concentrated among smaller segments of the population
C) when there is a great possibility that a vast number of citizens will become free-riders
D) when the choices made by the government match the preferences of the median voter