The scenario described involves the partition of India in 1947, which resulted in the displacement of approximately 17 million individuals. This mass displacement was largely driven by the creation of two separate nations—India and Pakistan—based on religious lines, leading to widespread communal violence and persecution.
Given this context, the most appropriate reason for migration in this case is forced political migration. The partition led to individuals being compelled to leave their homes due to the political and social upheaval surrounding the division, as well as the ensuing violence. Many moved to avoid persecution or conflict, making their migration a result of political circumstances rather than voluntary or economic factors.