In the context of maximizing utility within a budget constraint, which of the following scenarios best illustrates the utility-maximizing rule at market equilibrium?

The utility-maximizing rule states that consumers should allocate their budget in a way that equalizes the marginal utility per dollar spent on each good or service. This means that to get the most satisfaction from their spending, they should compare how much extra happiness (or utility) they gain from each dollar spent. For example, if Sarah has $10 to spend on apples and oranges, and she finds that the last apple gives her 5 units of utility and costs $1, while the last orange gives her 10 units of utility and also costs $1, she will get more satisfaction from buying oranges. At market equilibrium, Sarah will adjust her purchases so that she maximizes her total happiness without exceeding her budget, ensuring that the last dollar spent on each item gives her the same level of satisfaction. This careful balance of spending helps her achieve the highest overall utility possible within her budget.