Given the task definition and input, reply with output. 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".

A man attaches a baby stroller to the back of a bicycle. He puts the wheel on the stroller. he <sep> (A) sits on the back the stroller. (B) stands up next to the stroller. (C) then attaches a pressure washer to the back wheel. (D) takes the wheel off the stroller.
B