Although kim just ate a huge meal and feels "stuffed," the idea of a chocolate sundae is too good to pass up, so she orders one. which motivational term explains the appeal of the sundae?

I believe the answer is: Incentive motivation

Incentive motivation in this context refers to the motivation that derived from personal desire.

Compared to the motivation that imposed or expected by other people for us, incentive motivation tend to be stronger and way harder to control