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". 

Ex Input:
[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.

Ex Output:
D


Ex Input:
Multiple colors and designs flash across the screen. women <sep> (A) are shown completing pairs of women's first pair. (B) gather onstage as they are about to perform. (C) are interviewing a man in a room in front of an orchestra, with a man sitting on a couch nearby. (D) alternate with hairspray and styles to help themselves style, style, and style.

Ex Output:
B


Ex Input:
[header] How to improve your sleeping position [title] Put a pillow between your legs. [step] Sleeping on one side of your body is known to be one of the most comfortable positions and one of the most common. To make this position more comfortable, try putting a pillow between your bent legs. <sep> (A) [substeps] If you don't have the support of a good bed, you may like sleeping on your back instead. [title] Pick a pillow with a natural weight. (B) [title] Determine if you're flat on your back. [step] Not only is it common for your tailbone to feel restricted by your pillow, but it also puts pressure on your joints. (C) You can find pillows in cushioned sleeping bags or in foam boxes. [substeps] Some studies have shown that sitting with your lower legs out keeps your heart rate up, which can reduce snoring. (D) Slide the pillow between your knees and keep the pillow in place as you lay down on your side. This can help to protect your lower back and take the strain off your neck as you sleep.

Ex Output:

D