Final answer:
As Samuel consumes more ice cream cones, his total utility increases while his marginal utility decreases, which aligns with the law of diminishing marginal utility. Hence, the correct answer is (c).
Step-by-step explanation:
The student's question pertains to the relationship between Samuel's consumption of ice cream cones and his total utility and marginal utility. According to the law of diminishing marginal utility, as a consumer consumes more of a particular good, the additional satisfaction derived from each additional unit (marginal utility) tends to decrease.
Therefore, while consuming more ice cream cones would increase Samuel's total utility, his marginal utility for each additional ice cream cone would diminish. The correct option that matches this description is (c) his total utility increases, but his marginal utility decreases.