The correct answer is: d) All of the above
Long-term discontent among Indian soldiers (sepoys) stemmed from a variety of factors, including religious insensitivity, discrimination and limited promotion prospects, and fear of forced conversion.
Religious insensitivity was a major issue, as many sepoys were Hindus or Muslims who were offended by the use of Christian symbols and practices in the British army. For example, in 1857, sepoys were outraged when they were ordered to use cartridges that were greased with pig or cow fat, which was considered sacrilegious to both Hindus and Muslims.
Discrimination and limited promotion prospects were also major sources of discontent. Sepoys were paid less than British soldiers and were not allowed to hold the same ranks. This led to resentment and a feeling that they were not being treated fairly.
Fear of forced conversion was another major concern. Many sepoys believed that the British were trying to convert them to Christianity, and this led to a great deal of anxiety and suspicion.
All of these factors contributed to the discontent that led to the Indian Rebellion of 1857.