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 plastic water tank [title] Open the outlet valve or tap. [step] The first step to cleaning your tank is to empty all of the water from it. To do so, open the outlet valve or tap at the bottom of your tank and let all of the water flow out. <sep> (A) [substeps] You may find that there's extra water in your tank that you need to empty. Read the instructions carefully to see if your water is full enough to remove. (B) You will have to remove several pieces of tank flooring to access one. For the best results, take the steps above. (C) Then, use a bucket to wipe the water down away from the water line, then gently empty the tank contents into the toilet. [substeps] You should also clean the water tank once every few months to keep it clean. (D) [substeps] Connect a hose to the open valve in order to direct the water to a location where it will not cause any localized flooding or erosion. Permanent water tanks have a washout valve that is located at the base of the tank.
A:
D