Answer:
Atmosphere
Step-by-step explanation:
The water cycle classifies the water reservoir as a surface or atmosphere. Water on the surface can be a lake, river or soil. This water will flow to the ocean, where it can easily get evaporated into water vapor.
Water on the atmosphere is not only water vapor, but it can also be snow or cloud so option A is wrong. Another option is describing the process that moves the water to different reservoir.