Answer
Total utility is increasing at a decreasing rate. This is due to the marginal utility decreasing as the units consumed increase.
Work Step by Step
Total utility is the amount of usefulness a product, or multiple products provide to a consumer (buyer).
Marginal utility is the amount of additional usefulness an extra unit of product provides to a consumer.
The table provided in the question states that as extra units of product are being consumed at a linear rate, the total utility increases, but the marginal utility decreases
