Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to make washing soda [title] Gather your supplies. [step] You will need a large metal baking dish (though stone or glass will also work), a one-pound (454 grams) box of baking soda, and a wooden spoon. [title] Preheat your oven to 400 f (204 c).

Ending1: [step] Grease a baking dish and line it with parchment paper. [title] Combine 1 1/2 cup (120 ml) baking soda , 1/2 cup (240 ml) of white vinegar, and 1 tbsp. Ending2: [step] If you have a stovetop, the closer you get to the temperature, the more quickly it will sink. [title] Mix the powdered sugar with the baking soda. Ending3: [step] Spray your baking dish with non-stick spray to prevent sticking to the bottom. [substeps] You can also use a bottle of non-stick spray, which you can find online or at your local craft or food supply store. Ending4: [step] Cover the bottom of the baking dish with a thin layer of baking soda. Baking a thinner layer that's about one-quarter inch (0.6 cm) thick will ensure that the process occurs uniformly.

Answer format: ending1/ending2/ending3/ending4