The correct answer is: Summer, monsoon, winter.
The state of Kerala, India, has a tropical climate with distinct seasons. The summer season is from March to May, and is characterized by hot and humid weather. The monsoon season is from June to September, and is characterized by heavy rains. The winter season is from December to February, and is characterized by cool and dry weather.
The other options are incorrect because they do not accurately reflect the climate of Kerala. Spring, summer, autumn, and winter are the four seasons in the temperate climate zone, which Kerala is not located in. Monsoon only is incorrect because Kerala does experience other seasons besides the monsoon season. All seasons are similar is incorrect because the seasons in Kerala are distinct from each other.