Suppose that Pete spends all of his income on pies and cookies. At the optimum consumption bundle, which of the following must be true? The ratio of the marginal utility of the last cookie to the price of the cookie is equal to the ratio of the marginal utility of the last pie to the price of the pie. O Pete spends all of his income on cookies and none on pies if cookies are cheaper. O Pete spends all of his income on pies and none on cookies if pies are cheaper. O The marginal utility of the last cookie equals the marginal utility of the last pie purchased