Which word describes the area below Earth's surface that fills with water?

The correct answer is "groundwater"

Explanation:

The missing options of this questions are:

floodplain

groundwater

kettle

sinkhole

The correct answer is "groundwater"

Groundwater is defined as the area below Earth's surface that fills with water. Groundwater is usually found in cracks and spaces within the ground, result of raining or snow melting. Groundwater is stored in these places and moves slowly towards larger reservoirs of stored water called aquifers.

The area below Earth's surface that fills with water is called the aquifers. It's where the groundwater accumulates.