Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to make rainbow cookies [title] Preheat the oven and arrange the oven racks. [step] To be certain the the oven is warm enough when you bake the cookie layers, it's important to preheat the oven. Set the temperature to 350 degrees fahrenheit (180 degrees celsius) and allow it to heat.

Ending1: [substeps] If you have a gas oven, you'll need to let the oven bake until you can mold some paper onto the top. The oven directions will tell you how long it will take to preheat or estimated cooking times. Ending2: Position the oven racks in the upper and lower thirds of the oven as well. [substeps] Be aware of how your oven indicates that it's preheated to the desired temperature. Ending3: [substeps] For golden or toasted loaf cookies, preheat your oven 30 minutes before baking time. [title] Combine 1 cup (237 ml) of confectioners' sugar and 3/4 cup (165 ml) of brown sugar. Ending4: Next, line the rack, except for the cubby hole, with parchment paper. [substeps] You'll need approximately eight cookie sheets.

Answer format: ending1/ending2/ending3/ending4