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:
An introduction comes onto the screen for a video about rock climbing and a man introduces what will happen in the video. a men in a blue shirt <sep> (A) is doing a jump and falling off, then he begins to climb along the rock face with another by him. (B) stands behind a rock wall talking. (C) is shown climbing all the way to the top of a rock. (D) and the interviewer is inside of a gate in a park and he begins by jumping up to the top of a roofed wooden fence to do various things.

Ex Output:
C

Ex Input:
[header] How to host a housewarming party [title] Make a guest list. [step] You should start keeping a guest list before you start working on the invitation. Be sure you include any friends, family, and coworkers that you would like to invite into your new home. <sep> (A) This will help ensure that the party is pleasant and enjoyable for your guests. Make sure that the guest list is segregated in different places. (B) [title] Decide ahead of time whether you will invite guests with a " weekly " or " annual " package. [step] You should also design and print out your invitations carefully and make sure they reflect how the party will look. (C) [substeps] Limit the guest list to the number of guests appropriate for the amount of space you have available. If you have a small space, consider hosting 2-3 smaller parties rather than one big one. (D) This way, parties are easier to plan without the need for many less specific guests. [substeps] Include guests that you know will be a good fit for your home's atmosphere.

Ex Output:
C

Ex Input:
[header] How to make barbacoa [title] Puree the sauce ingredients. [step] Combine the chopped onions, olive oil, garlic, cumin, oregano, chiles, cider vinegar, and salt in a blender or food processor. Blend the ingredients together at medium to high speed until a thick puree forms. <sep> (A) [substeps] Puree the sauce until it is smooth but you have pureed all the ingredients and are still shaking it. This can take anywhere from a few minutes to several hours. (B) [substeps] Do not over puree the sauce. The stain of the maillard sauce will prevent it from adequately processing. (C) [substeps] Do not drain the adobo sauce from the chipotle chiles before adding them. You should pour the sauce into the blender along with the chiles. (D) [substeps] If using taco seasoning, pulse the mixture until it becomes thick. Place it back in the blender and pulse again until it forms smooth.

Ex Output:
C