Which one of the following should contain maximum DO?ans.Ground waterLakemolten glacier and ice capsRiver

The question is asking which of the following options should contain the maximum Dissolved Oxygen (DO):

1. Ground water
2. Lake
3. Molten glacier and ice caps
4. River

Dissolved Oxygen (DO) is the amount of oxygen that is present in water. It is an important measure of water quality as it indicates a water body's ability to support aquatic life.

Here's a step-by-step analysis of each option:

1. Ground water: Ground water is usually low in DO because it is not exposed to the atmosphere and there is little to no photosynthetic activity.

2. Lake: The DO levels in lakes can vary. Surface water in contact with the atmosphere can absorb oxygen, and photosynthetic activity by aquatic plants can also contribute to DO levels. However, deeper parts of the lake, especially in stratified lakes, can have low DO levels due to decomposition processes.

3. Molten glacier and ice caps: Glacial meltwater can have high levels of DO because cold water can hold more dissolved oxygen than warm water. Moreover, the process of melting can incorporate atmospheric oxygen into the water.

4. River: Rivers can have varying levels of DO. Fast-moving rivers can absorb oxygen from the atmosphere, and photosynthetic activity can also contribute to DO levels. However, pollution and high temperatures can decrease DO levels.

Based on this analysis, molten glacier and ice caps should contain the maximum DO due to their cold temperatures and the process of melting incorporating atmospheric oxygen into the water.