Definition: 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: People are sledding down a snowy hill on an inner tube. they <sep> (A) stop at the bottom of the hill. (B) are in the snow on their bellies moving fast. (C) get on the inner tubes and begin walking down the hill to the end. (D) pass several tunnels and platers.
Output:
A