Instructions: 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".
Input: [header] How to keep a dog in the yard [title] Observe your dog while he is in the yard. [step] Figure out how your dog is getting out of your yard, sit by a window and watch him while he is outside. Try not to let him see you or he may not reveal his escape route. <sep> (A) [substeps] This could be by window or inside your home, or it could be through a regular door in your home with a dangling shutter to allow him outside. [title] Watch him as he moves out of your yard. (B) Practice a trick like lifting on a jump bar to see where he goes. The jump bar will help you spot where he is going and what he is doing when you catch him. (C) As you watch, pay attention to where your dog goes and what he does. This should give you clues about his preferred method of escape. (D) He may retreat to another area somewhere in the yard and get lost. [title] Follow your dog's lead when it comes to food.
Output:
C