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: A girl is riding on a yellow riding lawn mower on a very large yard filled with green grass. when the girl <sep> (A) makes it to the end of the lawn, she stops, takes a deep breath, gets off her horse and walks away. (B) stops, she is standing in front of an able to reach yellow dirt path to prepare her destination. (C) reaches the end of the yard she makes a turn and drives up in the same direction she just came from. (D) reach the end of the yard, she looked around and started to turn around and walk back to the beginning.
Example Output: C

Example Input: [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.
Example Output: C

Example Input: [header] How to determine if you should quit facebook [title] Notice how often you use facebook. [step] Start by considering how much time you spend on facebook on a daily basis. Do you change your facebook status every hour on the hour? Do you end up scrolling through your newsfeed for way too long? Do you tend to check your facebook a little too often? These may be signs that you are spending too much time on facebook. <sep> (A) [title] Analyze what you do on a daily basis. [step] If you review every day what you do on a daily basis is there are likely to be patterns in your daily habits. (B) [title] Notice if you report to facebook's news feed only. [step] Ask yourself if you spend more time gossiping, snooping around, or randomly checking facebook. (C) [substeps] You can also think about your facebook use on a weekly basis. For example, maybe you spend an average of two hours a day on facebook. (D) [substeps] Facebook often asks for news in a very new area of your life. If you only just met someone, they may ask you for notifications they haven't seen in awhile.
Example Output:
C