Which of the following is not a type of water source?

Mineral water is primarily defined as water that contains dissolved minerals and gases, often used for drinking and therapeutic purposes, but it does not serve as a fundamental source of water in the same way that the others do. The other types listed—rainwater, surface water, and groundwater—are essential sources of water that contribute directly to ecosystems and human usage. Rainwater comes from precipitation, surface water includes lakes, rivers, and streams, and groundwater refers to water stored beneath the earth's surface in aquifers. Thus, while mineral water can be consumed, it does not function as a basic water source that supports the hydrological cycle or meets broad community water needs.