If a product has a diminishing, but positive, marginal utility, then

A) total utility decreases at an increasing rate.
B) total utility will become negative.
C) total utility increases at a diminishing rate.
D) total utility decreases at a diminishing rate.

When a product has a diminishing, but positive, marginal utility, it means that each additional unit of the product consumed provides less additional satisfaction than the previous one, but still adds some level of satisfaction. Therefore, total utility continues to increase, but at a slower (diminishing) rate with each additional unit consumed.