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 make camera filters and special effects [title] Buy an inexpensive u.v filter (around $10) and smear vaseline on it to make the subject look " soft ". [step] Sometimes you can make it foggy looking, if you want to add fog in a landscape picture. [title] Also you can remove the uv filter, fog the lens with your breath, and then, before it evaporates, screw the filter back on. <sep> (A) [step] Another optional step is to get rid of old film and debris. [title] Put small pellets on the inside of frames and replace them with fine gravel. (B) [step] Here is some easy stuff to do. [substeps] Place the lens just outside camera aperture (if you have one). (C) [title] Use interesting pattern see-through cloths. [step] Take the cloth, put it over the lens, and tie a rubber band around it to keep it in place. (D) [title] Lightly dust the entire area with a cotton swab. [step] Fill a large clip with vaseline and place it on top of the lens.
Output:
C