View Full Document.  If total utility is at a maximum, then marginal utility is rising. Incorrect  If total utility is at a maximum, then marginal utility is at its average value. Incorrect  If total utility is at a maximum, then marginal utility is at a maximum. Incorrect  If total utility is at a maximum, then marginal utility is zero. (True Answer )Correct 531 The amount by which total utility rises when an additional slice of pie is consumed is called:  average utility. Incorrect  the law of diminishing returns.