The correct answer is A. oceans and seas.
Oceans and seas cover about 71% of the Earth’s surface, and they contain about 97% of the Earth’s water. The remaining 3% of the Earth’s water is found in glaciers and ice sheets (2.4%), groundwater (0.6%), freshwater lakes (0.02%), and water vapor in the atmosphere (0.001%).
Oceans and seas are important for many reasons. They provide a home for a wide variety of marine life, they help to regulate the Earth’s climate, and they are a source of food, water, and minerals for humans.
Groundwaters, rivers and streams are also important sources of water for humans. However, they only account for a small percentage of the Earth’s water.
Glaciers and ice sheets are the largest reservoirs of fresh water on Earth. However, they are also the most inaccessible.
Freshwater lakes are a source of water for humans and other animals. However, they are relatively small compared to oceans and seas.
Water vapor in the atmosphere is a very small percentage of the Earth’s water. However, it plays an important role in the Earth’s climate.