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 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.
Output:
A