The correct answer is: d) Coconut.
Kerala is the largest producer of coconuts in India and the second largest in the world. Coconuts are used in a variety of products, including coconut milk, coconut oil, coconut water, and coconut meat. They are also used in traditional medicine and in religious ceremonies.
Rubber is the second most important commercial crop in Kerala. Rubber is a natural latex that is extracted from the rubber tree. It is used in a variety of products, including tires, shoes, and gloves.
Tea is the third most important commercial crop in Kerala. Tea is a beverage that is made from the leaves of the tea plant. It is grown in tropical and subtropical climates.
Coffee is the fourth most important commercial crop in Kerala. Coffee is a beverage that is made from the beans of the coffee plant. It is grown in tropical and subtropical climates.
Rubber, tea, and coffee are all important commercial crops in Kerala. However, coconut is the most important commercial crop in Kerala.