What was the main reason for introducing income tax and raising customs duties in India during the First World War?

Correct answer: To meet war expenditure

During the First World War, the British government faced very high military and administrative costs. India was used as an important source of revenue, so income tax was introduced and customs duties were increased to raise funds for wartime expenditure. These measures were not intended to grant swaraj or release peasants from rent. Reducing dependence on foreign cloth became associated with later nationalist economic campaigns, not the main reason for these wartime taxes.