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:
A man demonstrates how to walk across and navigate a slackline in a grass courtyard in front of apartments. the man <sep> (A) demonstrates how to traverse a low brick fence on a residential street. (B) walks slowly across the slackline while talking and stopping to talk to passerbys. (C) stands on a slackline balancing himself with his arms before the clip cuts to him interviewing. (D) poles backward, glasses on and he begins to walk while holding the slackline while walking across the courtyard.

Ex Output:
C


Ex Input:
[header] How to download microsoft office 2010 [title] Visit the office 2010 download page. [step] Microsoft office can be legally downloaded from microsoft's website as long as you have a valid 25-character product key. To find it easily, search for " using your office 2010 product key ". <sep> (A) [substeps] If you don't have a csso account, you may have to create one. You will need to verify your identity with microsoft office 2010. (B) [substeps] Office 2010 is no longer available for purchase or as a trial from microsoft. You can still buy boxed copies from other retailers. (C) [substeps] Leave one or more lines between the tabs on the homepage and the window you will be downloading to provide information about what you want to download. [title] Open the primary file you wish to download. (D) [title] Enter the windows code to install microsoft office 2010. [title] Click on the save file to run the pc then re-open microsoft office 2010 now to continue.

Ex Output:
B


Ex Input:
A young man is rappelling up the side of a cliff. Another man watches and helps from below. the man <sep> (A) continues climbing until he reaches the top. (B) is rappelling down the cliff using ropes. (C) makes a complete 360 turn in the air before coming back to the top of the cliff. (D) lets go from the rope, and is seen again.

Ex Output:

A