If You Wanted to Encourage Kindergartners to Delay Gratification, You

If you wanted to encourage kindergartners to delay gratification, you would most likely:

A) tell them that how well they behave at the end of the day is really what counts.
B) ask them to focus on how good it feels to do something nice for a classmate.
C) talk about how their learning efforts today will pay off in the years to come.
D) occasionally remind them that they will get a bigger reward by waiting a couple of hours.