Detailed Instructions: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
Problem:[header] How to use a double boiler [title] Gather your materials. [step] You will need both the bottom pot and the upper pot; you will not need the lid that came with your double boiler, unless the recipe or project specifically calls for one. If you do not have a double boiler, you can make your own using a large pot and a shallow, heat-resistant bowl that can fit over it. <sep> (A) [substeps] The bottom pot should be made of ceramic, as these are the most common, and should withstand high temperatures. The front pot should be made of glass, as these can get splashed with hot water. (B) [substeps] The bowl in your homemade double boiler should fit snugly onto the large pot. There should be no gaps or spaces between the bowl and the rim of the pot. (C) [substeps] The bottom pot should be big enough for two people to mix using, and must hold at least 1 cup (240 ml) of water in it. Place the container with the siphon filling in the bottom pot. (D) [substeps] You can use a large pot or pour boiling water in a smaller pot. Use a metal bowl if it can fit over the pot and then place your middle pot on top of the double boiler.
Solution:
B