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: A group of men are in a sandy desert. they <sep> (A) climb on top of camels and ride them. (B) are wearing rafts, and seated in them, they navigate the rough waters of a river. (C) are paddling through the water, using handgrips and oars. (D) are parasailing on the sea bed.
A:
A