Question 3 1 pts In the purist form of the theory of optimal income taxation, we have some pretty strict assumptions. Some of these barely match real life and some of them just don't work at all in real life. The following assumption does not work at all in real life and makes this model unusable: O The assumption that everyone has the same utility function 0 The assumption that utility functions exhibit rising marginal utility of Income 0 The assumption that utility functions exhibit diminishing marginal utility of income 0 The assumption that total amount of income in society is xed