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: We see a man teaching others to sharpen a knife in a butcher shop. The man wets the sharpening stone. Two men in the back laugh at something. the instructor <sep> (A) shows us a basket of pennies. (B) checks the knives and uses the sharpened knife to sharpen a one. (C) uses a sharpening rod for the knife. (D) puts a paper in the sink.
Output:
C