In this task, you will be presented with the directions of a recipe separated by "," and have to fill in the "___" which is a step that is missing from the recipe.
Q: Butter the bottom of a 13 x 9 1/2-inch pan.,Cut rhubarb to cover bottom of pan.,Spread sugar over rhubarb.,______,Mix cake mix according to directions.,Put over rhubarb mix and bake for 25 to 30 minutes.,Cool and serve as upside down cake.
A:
Spread jello over rhubarb.