Describe the water cycle's key processes and how they sustain life on Earth.

• A. Evaporation, condensation, precipitation, infiltration, and runoff move and purify Earth's water, supporting drinking water, habitat, and plant growth.
• B. Photosynthesis, respiration, decomposition, combustion.
• C. Erosion, sedimentation, weathering, deposition.
• D. Subduction, melting, crystallization, weathering.

Answer: (A)

The water cycle describes how Earth’s water moves and is renewed, using evaporation, condensation, precipitation, infiltration, and runoff to keep water circulating between air, land, and oceans. Evaporation (and plant transpiration) lifts water into the atmosphere; condensation forms clouds; precipitation returns water to the surface. Some water infiltrates the soil, recharging groundwater that plants and animals rely on, while runoff carries water over the land into streams and rivers. This continuous cycling distributes fresh water, supports drinking water sources, and provides the moisture needed for habitats and plant growth, sustaining life.

Biological processes like photosynthesis and respiration, and geological processes such as erosion, weathering, or plate tectonics, describe different phenomena and don’t capture the cyclical movement and purification of Earth’s water.