Which is not a source of fresh water?  A. Glaciers and ice sheets  B. Groundwater  C. Surface run off  D. Oceans

Break Down the Problem

1. Identify all the options provided in the question regarding sources of fresh water.
2. Determine which of these options does not qualify as a source of fresh water.

Relevant Concepts

• Fresh water sources include glaciers and ice sheets, groundwater, surface runoff, and rivers and lakes.
• Oceans are made up of salt water and are not considered a source of fresh water.

Analysis and Detail

1. Glaciers and Ice Sheets: These store a significant portion of the world's fresh water.
2. Groundwater: This is a known source of fresh water stored underground.
3. Surface Runoff: This includes water from rain or melting snow that moves across the land and eventually flows into rivers, lakes, and oceans; it also contributes to the fresh water supply.
4. Oceans: Contain salt water, therefore do not contribute to fresh water supplies.

Verify and Summarize

Upon analyzing each option, it is clear that glaciers, groundwater, and surface runoff all are sources of fresh water, while oceans are not.

Final Answer

D. Oceans