Answer:
d. all of the above
Step-by-step explanation:
The atmosphere stores water in the form of water vapor (a potent greenhouse gas).
The ground stores water as "groundwater" in soil and rocks. Some of it is above ground in lakes, streams, and wetlands.
The ocean is a large reservoir of water.
So, "all of the above" is an appropriate choice for where water is stored.
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In addition, a considerable amount of water is stored in living things ("biomass"), most of which are mostly water.