A Critical Assumption in Economist A

A critical assumption in economist A. P. Lerner's theory explaining why society's total utility is maximized with income equality is

A) there is no "level playing field" in people's choice of employment
B) people have identical utility functions
C) the rich earn their income by exploiting the poor
D) people have equal skills if given equal opportunity
E) the law of diminishing marginal utility does not apply to money