After the British divided their Indian Empire into the independent countries of India and Pakistan in 1947, millions of people fled their homes across the newly drawn borders. This mass migration was accompanied by horrific violence and communal riots between Hindus and Muslims, leading to significant loss of life and suffering. The partition resulted in approximately 10-15 million people being displaced, and the violence claimed hundreds of thousands, if not millions, of lives.
The other options mentioned, such as the Congress Party's restrictions on the rights of Pakistani Muslims in India and the various agreements between India and Pakistan, are not accurate reflections of the immediate aftermath. While there were tensions and disputes between the two nations, particularly concerning Kashmir and the rights of minorities, the most immediate and notable impacts were the mass migrations and violence.
Additionally, while China did take advantage of the regional instability later on, particularly regarding border disputes, this was not a direct consequence of the partition itself.