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: Letters are shown on a screen. a blue bucket <sep> (A) is filled with dirty water and slowly filled with soap. (B) is filled with chocolate milk. (C) is put into a sink. (D) is covered in water.
Output:
C