The primary staple food crop of Assam is:

Wheat
Rice
Maize
Pulses

The correct answer is (b) Rice.

Rice is the primary staple food crop of Assam. It is grown in the Brahmaputra Valley, which is the most fertile region of the state. Rice is a cereal grain that is cultivated in flooded paddy fields. It is a major source of carbohydrates, dietary fiber, and protein for people around the world.

Wheat is a cereal grain that is cultivated in dry, non-flooded fields. It is a major source of carbohydrates, dietary fiber, and protein for people around the world. However, it is not a major crop in Assam.

Maize is a cereal grain that is cultivated in dry, non-flooded fields. It is a major source of carbohydrates, dietary fiber, and protein for people around the world. However, it is not a major crop in Assam.

Pulses are a group of legumes that are cultivated in dry, non-flooded fields. They are a major source of protein, dietary fiber, and vitamins for people around the world. However, they are not a major crop in Assam.