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 make healthy mashed potatoes [title] Wash and cut the potatoes. [step] Wash 1 1/4 pounds (567 g) of your potatoes. You can also use a mix of potatoes and root vegetables for a variety of nutrients. <sep> (A) You can discard the peels, pits, and skins to make only healthy mashed potatoes. [substeps] The mashed potatoes will have a mildly sour texture after this step. (B) Leave the skin on the vegetables and cut them into 1-inch (2.5 cm) pieces. [substeps] Ensure that the pieces are the same size, so they cook evenly. (C) Wash the potatoes out of a colander and rinse them under clean running water. Then rinse each potato under cool, running water for about 5 seconds to remove dirt. (D) Wash the potatoes under hot tap water so they're soft and ready to eat. [substeps] Fresh or frozen mashed potatoes will last 7 to 10 months.

Ex Output:
B

Ex Input:
The boy is now back on his dirt bike and once again the drone can be seen flying along. a close up of the drone flying in the sky <sep> (A) is seen then he is shown faster, only this time it is in slow motion and once again the middle of his very pink face is shown and he's back on his dirt bike and watching the boys work again. (B) throwing a ball of fire, then comes back and forth as he attempts to keep up with the back highway traffic back in the area. (C) is shown and white words appear on the screen that say " phantom 2 vision + let your imagination take flight ". (D) looks so easy and after another battle scene of people being devoured by the drone, more hours pass and also more hours of grass are shown being constantly mowed.

Ex Output:
C