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 a hot water dispenser [title] Wet a cloth with a cleaning solution. [step] Generally, a mild cleaning solution will do. For instance, you can add a dash of dishwashing soap to 4 cups of water (about a liter). <sep> (A) [substeps] In a closed shower, warm water saturates the cloth and will plug up the hot water spots. You can also wet a paper towel with a wet substrate cleaning solution. (B) [substeps] Use soap specifically designed for cleaning cloth buckets. Too much salt can contaminate hot water. (C) That's it; an unlimited amount. Dip a towel in the solution, then wring it out. (D) Mix it up, then dip your rag in it to wet it. [substeps] Skip bleach solutions, particularly on stainless steel.
A: 
D