Final answer:
The situation consistent with the law of diminishing marginal utility is option B.
Step-by-step explanation:
The situation consistent with the law of diminishing marginal utility is option B, The more pizza Joe eats, the less he enjoys an additional slice. The law of diminishing marginal utility states that as a person consumes more and more of a good, the additional satisfaction or utility they derive from each additional unit decreases. In this case, as Joe eats more pizza, the enjoyment or utility he receives from each additional slice diminishes.