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: A man in a green shirt and green hat is holding a large knife. he <sep> (A) is sharpening a knife with a ruler. (B) starts cutting a piece of wood with the knife. (C) is sharpening a knife on a piece of a table. (D) starts sharpening a knife with a long thin knife.
Output:
B