Detailed 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".
Q: One of the tubers comes on a blue tube wearing a yellow helmet and blue vest is followed by several tubers also on blue tubes. they <sep> (A) are the fastest going of all the tubers, and are going really fast and making big passes in the air. (B) all get to the tube and begin drinking out of the liquids while going over the top. (C) go down the river on the their tubes as they try hard to stay afloat on the turbulent waves. (D) both arrive at the car while the other tubers are pushing on the bags.
A:
C