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: The man is hunched over on the the ground trying to build a fire by himself. It's all about adding oxygen at the right time once you have started a nice fire. also <sep> (A) , the cameraman goes to stand up to help the guy who's in the crouch position as the camera guy films them and makes notes. (B) , the guy rushes to get a bigger one. (C) , the man is not lying flat on the ground as he is trying to put firewood into the fire on the ground. (D) , if the fire is dead or dying you just hit it with a little bit more oxygen and it will help bring it back up.
Example Output: D

Example Input: Man is interviewing some people who is watching two women in bikini wrestling, the woman wins and start jumping. two women in bikini <sep> (A) are standing with a dwarf and he is winning the fight while the interviewer is talking to people in the audience. (B) threw down the metal bar and continue wrestling, of course some people are standing in the pool watching them. (C) wrestle second style in the track and field and win and walk to finish the event. (D) are returning to training with trampoline sits on a beach.
Example Output: A

Example Input: [header] How to identify atrial fibrillation [title] Monitor any breathlessness you experience. [step] When your heart starts beating quickly, as it does when you have atrial fibrillation, the rest of your body gets less blood supply because your heart is beating less efficiently. When your body's blood supply slows down, oxygen levels in your blood decrease, which will make you feel like you can't catch your breath. <sep> (A) [substeps] Dilation is when the blood vessels in your heart contract. Stopping them helps blood flow more effectively and allows more blood to be drawn from the heart. (B) [substeps] Your heart isn't pumping as quickly as normal when you have atrial fibrillation. This can make it harder for the heart to work smoothly. (C) [substeps] You may experience this feeling of breathlessness when you are climbing the stairs, exercising, or simply just walking. [title] Notice if you feel like your heart is pounding. (D) But even if your heart stop beating rapidly, that still means your heart is not working efficiently or is working too fast. This is called atrial fibrillation.
Example Output:
C