Answer:
A. Hinduism losing favor in India
Explanation:
The Muslim conquests on the Indian subcontinent started as early as the 8th century, though at that time they were very limited on only small areas on the fringes of the region. As the time was passing, the small sultanates managed to gain more and more followers which abandoned the Hinduism and accepted the Islam. This gave them much more power, so gradually the Muslim conquests were expanding throughout India, with multiple smaller sultanates being created. The major Muslim conquest though came with the invasion of the Mughals. They were a very powerful force, and managed to get under their control big portion of India, heavily influencing parts of the region and converting lot of people to Islam on the expense of the Hinduism.
