The immediate cause of the Mutiny of 1857 was the use of greased cartridges in the new Enfield Rifle. Soldiers in the British Indian Army were required to bite off the ends of the cartridges before loading them into their rifles. The cartridge paper was greased with animal fat, which offended both Hindu and Muslim soldiers, as it violated their religious beliefs. Hindu soldiers believed that the cartridge made them lose their caste status, while Muslim soldiers considered the use of pig and cow fat disrespectful. This led to widespread discontentment among the soldiers and sparked the rebellion. The introduction of railways and telegraphs (option 4) did contribute to the broader political, economic, and social changes in India, but it was not the immediate cause of the Mutiny.