Henry George's Single-Tax Movement Was Based on the Argument That

Henry George's single-tax movement was based on the argument that

A) the tax structure should consist solely of a highly progressive tax on nonwage incomes.
B) interest is unearned income and should be taxed away by government.
C) in less-developed countries the supply of and demand for land will be such that land will be a free good and therefore capable of bearing sizable taxes.
D) a high tax on land rent is justified because land rent performs no incentive function.