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:
[header] How to be creative with landscaping [title] Construct a playground for children. [step] Do not purchase expensive sets of see-saws, slides or swings. You can actually create a playground for children with just a few easy tweaks. <sep> (A) Explain to the children that you own a playground. If you have an old playground for young children, it may be easier for them to understand. (B) You can make use of old chairs or tires and turn them into swings. You just have to make sure that you use sturdy ropes as well as tie them appropriately to a tree for safety. (C) [substeps] Most likely, you would have made the playground yourself, but if you use it, you will need to provide very clear, patient instruction. On the playground's exterior, get creative and use the distinctive textures listed above. (D) [title] Consult with your local park or garden center to see if they can create their own playground. [step] Make sure that they can match the basics of an playground.

Ex Output:
B


Ex Input:
[header] How to change in a school locker room [title] Wear clothes that are easy to take off and put on. [step] On the days that you have gym class, make sure you wear stuff that's easy to get in and out of. Stick to shoes that are easy to lace or slip on, and pants and a top that are easy to take off on gym days. <sep> (A) [substeps] Gym classes always start with a gym uniform, and vice versa, so you'll want to wear more and less of these for each class. For example, you may wear a pair of jogging shorts for gym class. (B) You'll be able to get out of these clothes-and into your gym clothes-quickly. [substeps] For example, skirts with elastic bands, comfortable jeans, pullover shirts, and slip-on flats are great options for gym days. (C) [title] Make sure your locker is locked all the time and you cannot get in. [step] You'll be surprised how different locker rooms look. (D) [substeps] If you're at a new school, make sure to set the dress code. If you can, try to keep your clothing conservative or there won't be any nervousness or difficulty on gym day.

Ex Output:

B