A cross-country runner is willing to trade four one-quart bottles of Gatorade (Q) for a one-gallon bottle of Gatorade (G). Both goods make the runner happy and her preferences for Gatorade do not change along her indifference curve (IC).

(i) Sketch an IC on a two-dimensional diagram that shows the runner's preferences for Gatorade.

(ii) Carefully show if the runner's IC exhibits a diminishing, increasing, or constant marginal rate of substitution. Given your answer, what type of goods are gallon and quart bottles of Gatorade; perfect complements, imperfect substitutes, or perfect substitutes?