Sikkim is known for its cultivation of:

Rice
Wheat
Tea
Cardamom

Sikkim is known for its cultivation of cardamom. It is the largest producer of cardamom in India and the second largest in the world. Cardamom is a spice that is used in a variety of dishes, including curries, desserts, and beverages. It is also used in traditional medicine.

Rice is another important crop in Sikkim. It is grown in the lower elevations of the state. Wheat is also grown in Sikkim, but it is not as important as rice or cardamom.

Tea is grown in the higher elevations of Sikkim. It is a popular tourist attraction, and there are many tea gardens that offer tours and tastings.

The correct answer is (d).