The correct answer is: a) Rice.
Rice is a cereal grain that is widely cultivated in waterlogged areas of Assam. It is a staple food for millions of people around the world, and is also used in a variety of other products, such as rice paper, rice wine, and rice flour.
Jute is a long, soft fiber that is used to make a variety of products, such as burlap, twine, and carpet. It is a major crop in Bangladesh and India, and is also grown in Assam.
Wheat is a cereal grain that is used to make bread, pasta, and other baked goods. It is a major crop in many parts of the world, but is not grown in Assam due to the high rainfall and humidity.
Sugarcane is a tall grass that is used to make sugar. It is a major crop in many parts of the world, but is not grown in Assam due to the high rainfall and humidity.