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 woman work out in a rowing machine pulling a string with a handle. the woman <sep> (A) moves in the seat backward and forward while pulling the handle. (B) holds onto the handle with a second hand and works out on a machine with her foot. (C) is running around moving her arms back and fourth pushing the bolts and checks that her oar is properly in place. (D) stops and things explains.
A