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 sleep while sitting up [title] Gather bedding. [step] If you have time to prepare before trying to sleep upright, gather bedding such as a blanket, pillows, towel, or a mat. This bedding will make you more comfortable, and reduce any soreness from sleeping upright. <sep> (A) [substeps] Wearing loose, comfortable clothes and light shoes will also make it easier to sleep while sitting up. A special travel pillow can provide support for your head and neck. (B) [substeps] Determine what time you will sleep, and how much time you want to remain upright. Make sure to lay down tightly so that you can breathe easily and elevate your head at all times. (C) [substeps] The second most important thing to consider is the appearance. If you stay up all night, you will be better rested when it comes to sleeping in a position where you are not trying to move. (D) [substeps] Make sure to gather all your bedding in the same sitting position. If your feet are touching, leave more pillows or blankets on your legs to create the illusion of height.
Output:
A