Given the task definition and input, reply with output. 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".

[header] How to make kvass [title] Put 1.5 liters of water into a pot and bring it to a boil. [step] For this recipe you will need 1.5 liters (0.4 us gal) of water. You can make more or less at a time, but make sure to scale ingredients properly. <sep> (A) [substeps] Covering the pot will make the recipe easier for customers and helps increase doproduction and growth of the ingredients. [title] Pour 1 1/2 liters (0.17 us gal) of salt into the water and add 5 drops of raspberry blossom oil. (B) [title] Take 2 slices of rye or pumpernickel bread. [step] Toast them in a toaster on maximum settings. (C) [title] Boil the water until the sugar dissolves. [step] It can take 2 to 3 minutes for the sugar to dissolve in the water, as indicated on the packaging. (D) [substeps] It is better to have one liter of water than multiple liters of water at once. You can also try adding 1 cup of milk at a time into the water without boiling.
B