(a) Peasant resistance to the oppressive conduct of planters

(b) Its unprofitability in the world market because of new inventions

(c) National leaders’ opposition to the cultivation of indigo

(d) Government control over the planters

Answer: b

Explanation:

In Champaran under the tinkathia system the European planters had agreements with the Indian peasants. Indigo was cultivated on 3/20th land under this system .

In the early twentieth century, there was decreased demand for Indigo globally because of invention of German synthetic dye in late 19th century .

Synthetic dyes forced indigo out of the market. Inorder to release cultivators from the obligation of cultivating indigo planters enhanced rents, which was resisted by peasants. Exaction of planters continued. On the invitation of Rajkumar Shukla, Gandhi reached Champaran to investigate the problem.

Hence, option b is correct.

Read: Previous Year UPSC History Questions (PYQs) With Explanation 2020