In the case of two goods, \(x\) and \(y\), which of the following statements is most likely true? Maximum utility is achieved:

A. along the highest indifference curve below the budget constraint line.

B. at the tangency between the highest attainable indifference curve and the budget constraint line.

C. when the marginal rate of substitution is equal to the ratio of the price of good \(y\) to the price of good \(x\).