Final answer:
Buddhism almost disappeared in India due to forced migration, conversions to Islam, and the change in the nature of the religion.
Step-by-step explanation:
Buddhism almost disappeared in India for several reasons. One reason is that many Buddhists were forced to flee or be executed, causing them to migrate to Southeast Asia, Nepal, or Tibet where Buddhism remains a major religion today. Another reason is the conversion of many Hindus to Islam in the northern areas of the Indian subcontinent, which led to Islam becoming the majority religion in the region. Additionally, Buddhism lost some of its original character as it became institutionalized and attracted the patronage of elites, evolving into a religion focused on monunmental architecture and high art.