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:
[header] How to handle a dog's nightmares [title] Decide whether to wake up your dog. [step] When your dog is having a nightmare, your first instinct may be to wake up your dog. However, this isn't always the best idea. <sep> (A) Waking up your dog would disrupt its sleep cycle, causing it to feel confused and possibly lash out at you. It's often better to let a dog continue sleeping through the nightmare. (B) If your dog's nightmares persist and you aren't willing to take the time to monitor your dog, it might be best to enlist the help of a veterinarian. There are several reasons for this : [substeps] When your dog is having a nightmare, your own judgment is impaired. (C) If your dog is claustrophobic or is fear fearful, you will want to be as calm as possible while your dog is having the nightmare. If the fear is mild to moderate, choosing an alternative position or location may not be a good idea. (D) While nightmares are real, traumatic experiences can also happen. [substeps] Nightmares also occur in dogs that have nightmares caused by trauma.

Ex Output:
A

Ex Input:
[header] How to breed chihuahuas [title] Adopt a chihuahua to breed. [step] If you don't already have a chihuahua, you will need to get one that is ideal for breeding. Contact a breeder that specializes in breeding chihuahuas. <sep> (A) If you are looking to adopt a chihuahua you can breed, you should get it from a well-established and humane breeder that has solid documentation of its lineage. [substeps] Make sure your potential dog is in good physical and mental shape. (B) This is a good option for investors that want to go through a breed-specific final selection process before purchasing a dog from one of the breed-specific breeders. [substeps] Breed chihuahuas can learn complicated rules, including you will need to breed them yourself, or you may be able to substitute a dog from a previous relationship with one that is already bred. (C) Look around for a unique breed, preferably one that offers a wide variety of features. Remember to pay attention to age, as a young chihuahua is a rodent, and a healthy small baby chihuahua needs to be training and raised carefully. (D) Shop around a few different places before settling on one that is right for you. [substeps] Get a volunteer or mentor for this breed.

Ex Output:
A

Ex Input:
A female gymnast spins and flips on a high beam. a man <sep> (A) watches from a parallel beam. (B) who is likely her coach is spotting and training her. (C) and woman stand on the edge of a beam. (D) vaults up after her.

Ex Output:
B