Over the past few decades, income inequality in the united states, measured by the relative shares of total income earned by the top and bottom 20% of individuals, has increased. which of the following represent plausible causes of income inequality? check all that apply. a. some people choose to work longer hours than their peers. b. some individuals become wealthy by chance, while others have bad luck. c. some risk-takers end up earning exceptionally high incomes, while other risk-takers end up failing and earning little or no income. d. differences in ability make some people more adept at earning income than others.