Explanation:

- Option 1: Kolkata - It's one of India's largest cities and a major cultural hub. However, it does not have the highest population among metropolitan areas as per the 2011 Census.

- Option 2: Chennai - Known for its booming automotive industry and cultural heritage. Though densely populated, it's not the most populated metro.

- Option 3: Mumbai - It's the financial capital of India and indeed the most populated metropolitan city according to the 2011 Census.

- Option 4: Delhi - While close in population and growing rapidly, it's slightly behind Mumbai in the 2011 Census figures.