Because they needed the protection of the East India Company (EIC) to preserve the Mughal authority. After one century of prosperity the Mughal empire was facing its own decline. Different emperors raise to throne and did very little to save the empire from its collapse.
They faced several fights among claimers to the throne and eventually civil war. Much of the Mughal treasures were looted. In response, the British from the EIC gained trading rights, such as collect taxes, and ultimately political power.
C.) expanding pensions for civil war veterans and increasing federal government purchases of silver
The answer would be : a convention.
Hope this helps !
Photon
