The correct answer is cool.
The word “cool” is an adjective that means “having or giving a pleasant feeling of moderate coldness.” It is the most appropriate word to describe the shade of a banyan tree because it is a large tree with many branches that provide a lot of shade. The shade of a banyan tree is often cool and refreshing, especially on a hot day.
The other options are not as appropriate. The word “cold” is an adjective that means “having or giving a feeling of great coldness.” It is not as appropriate to describe the shade of a banyan tree because it is not usually very cold. The word “cooling” is a verb that means “to make or become cooler.” It is not as appropriate to describe the shade of a banyan tree because it is not usually in the process of becoming cooler. The word “dark” is an adjective that means “not giving or reflecting much light.” It is not as appropriate to describe the shade of a banyan tree because it is usually not very dark.