Detailed 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".
Q: [header] How to exercise in bed [title] Do push-ups. [step] Push-ups are a classic exercise that can increase arm strength. You can also easily do them from your bed. <sep> (A) Sit in the same position as you would if you were in bed; as long as your back doesn't hurt, and your feet are comfortably on the floor, you're good to do push-ups. [substeps] To do a push-up, lie on your side. (B) Reach into your drawer to find and complete three sets of six to 12 reps each. Doing push-ups with the help of a chair or wall can give you access to very useful exercise pieces. (C) To do push-ups, stand with your feet shoulder-width apart. Raise your arms above your head and legs up into the air. (D) [substeps] Place your knees or toes and your hands on the bed, while keeping your back straight. If you're a beginner, it's a good idea to use your knees over your toes.
A:
D