Indigo cultivation in India declined by the beginning of the 20th cent

Indigo cultivation in India declined by the beginning of the 20th century because of

peasant resistance to the oppressive conduct of planters
its unprofitability in the world market because of new inventions
national leaders' opposition to the cultivation of indigo
Government control over the planters
This question was previously asked in
UPSC IAS – 2020
The primary reason for the decline of indigo cultivation in India by the beginning of the 20th century was the invention and mass production of synthetic indigo dye in Germany in the late 19th century (especially from the 1890s onwards). This synthetic dye was cheaper to produce and of more consistent quality than natural indigo.
The advent of synthetic dyes made natural indigo cultivation economically unviable in the world market, leading to its decline.
Peasant resistance (A), such as the Indigo Revolt of 1859-60, did highlight the exploitative nature of indigo cultivation and led to some reforms, but it did not eliminate cultivation entirely; it continued under modified conditions. National leaders’ opposition (C), particularly Gandhi’s Champaran Satyagraha (1917), addressed the grievances of indigo cultivators but occurred later than the *beginning* of the decline caused by synthetic dyes. Government control (D) aimed at regulating the system rather than ending cultivation. The fundamental economic factor of unprofitability due to synthetic substitutes was the decisive cause for the decline by the early 1900s.