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". 

Example Input: [header] How to avoid the stomach flu [title] Wash your hands often. [step] Wash your hands carefully with soap and water for at least 20 seconds. Always wash your hands after going to the washroom and before and after handling food and eating. <sep> (A) Washing your hands is important, since if the way you handle and eat is bad (germs, bacteria, etc. ), your best chance at preventing the flu is by keeping your hands clean. (B) Don't attempt to dry or clean your hands on something other than a business table. [title] Wear long pants (not utility pants to wear running shoes with). (C) [substeps] It's a good idea to wash your hands between-and as many times as you go to the bathroom. This will help prevent an episode of nausea in the future, as well as allow your body time to shut down its internal defenses to fight off food, germs, and viruses. (D) This will help to prevent the spread of germs. Germs on your hands can get into your eyes, ears, and nose and make you sick.
Example Output: D

Example Input: [header] How to post to a facebook group on pc or mac [title] Go to https: // www.facebook.com in a web browser. [step] You can use any web browser, such as chrome or safari, to access facebook. If you're not already signed in, sign in now. <sep> (A) [title] Click on the downward-facing arrow in the top right corner of the screen. [step] It's at the top-right corner of the screen. (B) [title] Click your profile picture at the top-right corner of the page. [step] You will see your profile picture in the upper-right corner of the page. (C) [title] Click a group to open the group's menu. [step] Click the group on the right sidebar, or the group's upper menu of options. (D) [substeps] You must already be a member of a group to post to it on your computer. See join groups on facebook to learn how to join a group.
Example Output: D

Example Input: Two young man and a man play pool hitting white balls with a cue stick. The young man hits balls that land in the pocket of the pool table. then <sep> (A) they serve the ball with a cue stick. (B) , the young man attempts to hit hard balls to returned them, then he serves and misses 4 times. (C) , the young man wins and pushes another ball into the pocket. (D) , the man puts the balls in a metal triangle and arrange others balls.
Example Output:
D