The primary source of irrigation in Kerala is:

Rainfall
Canals
Tanks
Wells Answer: a

The primary source of irrigation in Kerala is rainfall. Kerala receives an average annual rainfall of 3,000 mm, which is more than twice the national average. This abundant rainfall is used to irrigate crops through a variety of methods, including canals, tanks, and wells.

Canals are artificial waterways that are used to transport water from rivers or reservoirs to fields. Tanks are artificial reservoirs that are used to store rainwater. Wells are holes that are dug into the ground to reach groundwater.

Rainfall is the most important source of irrigation in Kerala because it is a renewable resource that is available in abundance. Canals, tanks, and wells are all important sources of irrigation, but they are not as reliable as rainfall. Canals can dry up during periods of drought, tanks can overflow during periods of heavy rain, and wells can run dry if the water table drops.

Rainfall is also the most efficient source of irrigation because it does not require any energy to use. Canals, tanks, and wells all require energy to operate, which can be a significant cost. Rainfall is also the most environmentally friendly source of irrigation because it does not pollute the environment.

In conclusion, the primary source of irrigation in Kerala is rainfall. Rainfall is an abundant, renewable, and efficient source of irrigation that is also environmentally friendly.