The correct option is C Rumours of cartridges greased with the fat of cow or pig
In January 1857, there was a rumour in the Bengal regiments that the greased cartridge had the fat of cow or pig. The sepoys were now convinced that the introduction of greased cartridge was a deliberate move to defile Hindu and Muslim religion as the cow is sacred to Hindus and the pig is a taboo to Muslims. So, both the Hindus and the Muslims soldiers refused to use these cartridges and staged an uprising when they were forced to use them.