Definition: 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 lose weight fast (for the elderly ) [title] Walk for 30 to 40 minutes each day to burn about 200-350 calories. [step] This helps drain the excess body fat. [substeps] Walking exercise is suitable for you because it does not require too much movement. <sep> (A) Walking is both easy and good for tendons, bones, and your health. Walking helps to increase the body's metabolism and limits excessive accumulation of fat. (B) Take a walk every morning, a five hour walk on the treadmill or a run every day. This will help burn 20-300 calories and help with weight loss. (C) It's also a way to meet your healthy demands. [title] Do an activity that gets your blood flowing and improves your mood. (D) Improve your endurance and strength if you don't frequently take a walk. Don't be afraid to take a brisk walk or 3 shorter walks to stay active.
Output:
A