The correct answer is: a) Summer monsoon (June-September).
Mizoram is a state in northeastern India. It is located in the Western Ghats mountain range, which receives a lot of rainfall during the summer monsoon season. The monsoon season is from June to September, and it is the wettest time of the year in Mizoram. The average rainfall in Mizoram during the monsoon season is about 2,000 mm.
The winter months are from December to February, and they are the driest time of the year in Mizoram. The average rainfall in Mizoram during the winter months is about 50 mm.
The spring season is from March to May, and it is a transitional season between the winter and summer monsoon seasons. The average rainfall in Mizoram during the spring season is about 100 mm.
The autumn season is from September to November, and it is another transitional season between the summer monsoon and winter seasons. The average rainfall in Mizoram during the autumn season is about 150 mm.
Therefore, the most rainfall in Mizoram occurs during the summer monsoon (June-September).