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 walk silently [title] Watch where you walk. [step] Moving soundlessly is much more difficult when you're walking on crunchy gravel and leaves than it is when you're moving over soft grass or dirt. To walk silently, assess the terrain and determine which path is the quietest. <sep> (A) You can do this by buying a walking guide app on your smart phone. That way, you can listen for sound signals and observe the terrain closely. (B) Look for the gentlest routes available and choose one so that you can carry the pace for a long period. [substeps] It can help to have a flashlight handy too. (C) Whether you're indoors or outdoors, you can consciously walk over materials that help you move silently instead of creating extra noise. [substeps] If you're walking through the woods or in another outdoor area, try to walk on soft grass or dirt. (D) [substeps] If you're about 40 steps from the end of a pathway, then this may be a difficult path to take, even for beginners. When you're walking quietly, it's much harder to hear footsteps than if you're walking by a rockslide or on the shore of a lake or river.
A:
C