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".
Q: [header] How to clean burnt copper [title] Bring water and cleaning agent to a boil. [step] Fill a pot or pan with water. Add a few squirts of mild dish detergent and/or a generous splash of vinegar. <sep> (A) Bring this mixture to a boil over medium heat. [substeps] If you have a store-bought solvent for your copper, such as hydrogen peroxide, you don't need to add it to the water. (B) If you're cleaning anything other than a copper pot or pan (or cleaning the outside of a smaller pot or pan), place the item in the water. Set the burner to medium heat and bring to a boil. (C) The water shouldn't be too cold, though. Warm or cold water doesn't work very well on copper. (D) Turn your burner to high and bring the water to a boil over high heat. You'll need to keep the water at a simmer for about 30 minutes.
A:
B