Bihar became a major center of which cash crop cultivation during the British period?

The correct answer is: Jute.

Bihar became a major center of jute cultivation during the British period. Jute is a type of fiber that is used to make a variety of products, including burlap, gunny cloth, and jute bags. It is a major cash crop in India and Bangladesh.

Indigo is a blue dye that is extracted from the indigo plant. It was used to dye textiles and other materials. Tobacco is a plant that is used to make cigarettes, cigars, and other tobacco products. Cotton is a plant that is used to make textiles.

All of these crops were grown in India during the British period, but jute was the most important cash crop in Bihar.