Which of the following State has the longest spell of Monsoon Rains ?

The correct answer is (a) Kerala.

Kerala receives the longest spell of monsoon rains in India. The monsoon season in Kerala starts from June and ends in September. The average rainfall in Kerala during the monsoon season is 3,000 mm. The monsoon rains are essential for the agriculture and economy of Kerala.

The other options are incorrect because they do not receive as much rainfall as Kerala during the monsoon season.

(b) West Bengal receives an average rainfall of 1,600 mm during the monsoon season.
(c) Maharashtra receives an average rainfall of 2,000 mm during the monsoon season.
(d) Uttarakhand receives an average rainfall of 1,200 mm during the monsoon season.