The correct answer is: b) 1970s and 1980s.
The 1970s and 1980s saw a significant increase in in-migration into Assam. This was due to a number of factors, including the Indo-Bangladesh War of 1971, which led to the displacement of millions of people, and the economic development of Assam, which attracted workers from other parts of India.
The Indo-Bangladesh War of 1971 was a war between India and Pakistan. The war was fought over the issue of Bangladesh, which was then a province of Pakistan. The war ended with the creation of Bangladesh as an independent country. The war led to the displacement of millions of people, many of whom fled to India.
The economic development of Assam also led to an increase in in-migration. Assam is a state in northeastern India. It is a resource-rich state, and its economy has been growing in recent years. This has attracted workers from other parts of India, who have come to Assam in search of jobs.
The increase in in-migration has had a number of impacts on Assam. One impact has been on the state’s demographics. The population of Assam has increased significantly in recent years, and this has put a strain on the state’s resources. Another impact has been on the state’s politics. The in-migration of people from other parts of India has led to tensions between the indigenous people of Assam and the new arrivals.
The increase in in-migration is a complex issue with a number of causes and impacts. It is an issue that is likely to continue to be debated in Assam for many years to come.