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". 

Q: [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.

A: A
****
Q: 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.

A: C
****
Q: [header] How to avoid worsening persistent back pain [title] Get up and move around. [step] Research has shown that sitting too long cannot only contribute to back problems, but is bad for your health in general. Don't stay seated for long periods of time, whether at home or at a desk job. <sep> (A) A common risk factor for back pain is a sedentary lifestyle. Take a few minutes to stretch and walk around at least once per hour. (B) If you are unable to be active, consider moving into a reclining couch or recliner. Which position best benefits you most is a sofa. (C) Get up and stretch or make a change of positions or sit up straight in a chair. If you cannot do it just wait for it to dissipate and your doctor can do it for you. (D) Sitting for long periods can cause tension to build up, which can lead to achy and tight back pain. To help ease this tension, lie down and quietly clear your head.

A:
A
****