(3) Utility functions. Suppose John's utility function is 4XY, where X is consumption of beer and Y is consump- tion of pizza. We restrict our attention to the consumption bundles with both X > 0 and Y > 0. Which of the following statement is true? (A) The consumption bundle (6, 8) is on the mdiemnoe curve associated with the utility level 48. (B) John's marginal rate of substitution is given by 4X. (C) Y displays diminishing marginal utility for a given level of X. (D) The marginal rate of substitution diminishes as more of X is consumed