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 calculate a light year [title] Define the light year. [step] A light year is a measure of distance equal to how far light travels in one earth year. Because distances across the universe are so large, astronomers use light years. <sep> (A) However, they can also be determined by dividing by a distance. [substeps] Some light years are used year-round. (B) For light year 2014, the main determiner is the sun. In the light year, the world is filled with light bulbs. (C) Without light years, discussing the distance between two stars would require the use of large, unruly numbers. [substeps] Another measure of distance you may come across when learning astronomy is the parsec. (D) [substeps] There are two kinds of light years: day and night. The two types of light years are known as night and day.

A: C
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Q: [header] How to warm a horse's bit [title] Dunk in hot water, then wipe dry. [step] Heat water until it's just begun to steam, then bring it over to the stall in a bucket. Place a safety hook over the bucket and drape the bridle over it, making sure not to let the leather touch the water or the ground. <sep> (A) Dunk the bit for 10-15 seconds in hot water, or 1-2 minutes in lukewarm water. Wipe the bit down with a cloth to dry it. (B) Try to keep your head at least six inches from the water. The halter and bridle should be crimped, not tightened, to avoid fraying. (C) [substeps] You don't want the bridle to get hot. If this happens, you need to bring a band-aid or thick covering of newspaper over the cloth. (D) Smooth out any wrinkles so the bridle stays in place. [substeps] When you go to wash the bridle, look in the mirror to see if it fits.

A: A
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Q: [header] How to put music on facebook [title] Navigate to the website that features the music you want shared. [step] Examples of such websites are youtube and soundcloud. [title] Click on the " share " button located next to the music selection you want shared. <sep> (A) [step] You will be redirected to a page explaining to you exactly what music you want shared, and the category where it can be shared. [title] Click on " share " located below " share " in the drop-down menu. (B) [step] If you have multiple fans or listeners, you may see a link in the sidebar that says, " add a facebook friend to your friends list ". Click it if you want to add a facebook friend in the list. (C) [title] Scroll down until you see the right size. [step] If you are looking for music that is already on facebook, such as songs from a specific artist and/or a series of popular music videos, you will see the appropriate size. (D) [title] Select the option for facebook when asked how you want to share your selection. [title] Enter your facebook login information at the prompt.

A:
D
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