Explanation:

Insolation refers to the amount of solar radiation that reaches the Earth's surface. The amount of insolation received at different locations on the Earth's surface varies due to various factors such as the angle of incidence of the Sun's rays, atmospheric conditions, and geographical location.

Maximum insolation is received over the Sub-tropical areas. This is because of the following reasons:

1. Latitude: Sub-tropical areas are located between the Tropic of Cancer and the Tropic of Capricorn. These areas receive the most direct sunlight throughout the year, which leads to higher insolation.

2. Atmospheric Conditions: Sub-tropical areas usually have clear skies and low levels of atmospheric pollution. This allows for more solar radiation to reach the Earth's surface.

3. Geographical Location: Sub-tropical areas are often located in regions that are dry and have little to no vegetation. This means that there is less absorption of solar radiation by the Earth's surface, which leads to higher insolation.

4. Seasonal variation: Sub-tropical areas receive high insolation throughout the year due to the location. These areas do not have any distinct seasonal changes like the other regions.

Therefore, it can be concluded that maximum insolation is received over the sub-tropical areas due to their geographical location, atmospheric conditions, and latitude.