1.Independence of India (D): India gained independence from British colonial rule on August 15, 1947.

2.Green revolution in India (B): The Green Revolution in India began in the 1960s and continued through the 1970s. This agricultural transformation involved the introduction of high-yielding crop varieties, expansion of irrigation, modernization of management techniques, and more.

3.Economic crisis relating to India's external debt (C): India faced an economic crisis related to its external debt in the late 1980s and early 1990s. This crisis was a significant event in India's economic history.

4.Economic reforms in India (A): Economic reforms, often associated with liberalization and globalization, started in India in the early 1990s, following the economic crisis related to external debt. These reforms aimed to open up the Indian economy, deregulate various sectors, and promote economic growth.