The correct answer is option 3: Mumbai. Mumbai is the most highly populated city in India. It is the capital of the Indian state of Maharashtra and is located on the Western coast of the country. With a population of over 20 million people, Mumbai is not only the most densely populated city in India but also one of the most populous cities in the world. It is a major financial and commercial hub, home to the Bollywood film industry, and attracts millions of migrants from across the country in search of better opportunities.