In 1947, British Indian Empire was partitioned into the Dominion of Pakistan and the Union of India. What was the division line based upon?
watershed areas of Ganges and Indus
religious lines between Hindu and Muslim
British India was partitioned along religious lines into two states: the Muslim-majority Dominion of Pakistan (comprising what is now the Islamic Republic of Pakistan and the People's Republic of Bangladesh) and the Hindu-majority Union of India (later the Republic of India). This led to mass rioting amongst Hindus, Muslims and Sikhs. About twelve million refugees moved between the newly founded nations.