According to data cited by the World Economic Forum using United Nations Habitat figures, which Indian city was ranked as the second most densely populated city in the world with about 31,700 people per square kilometre?

Introduction / Context:
Urban population density is an important indicator in city planning and global comparisons. The World Economic Forum, using United Nations Habitat data, highlighted the world most densely populated cities, and one Indian city ranked second in that list. This question tests knowledge of that particular ranking and the associated population density statistic.

Given Data / Assumptions:

The ranking is based on data cited by the World Economic Forum and United Nations Habitat.
The city in question is in India.
It was ranked as the second most densely populated city in the world.
The density figure mentioned is around 31,700 people per square kilometre.
Four Indian cities are provided as options.

Concept / Approach:
The concept is general awareness of Indian metropolitan demographics. Mumbai is known for its extremely high population density and often appears in such global rankings. In the referenced list, Mumbai was placed second in terms of density, which is the key memory point needed to answer this question correctly.

Step-by-Step Solution:
Step 1: Recall which Indian city is most frequently described as extremely crowded and densely populated. Step 2: Link that city with international rankings that quote around 31,700 people per square kilometre. Step 3: Identify Mumbai from the options and select it as the correct answer.

Verification / Alternative check:
Articles from the World Economic Forum and analyses based on United Nations Habitat data show Mumbai near the top of world population density rankings, typically second after cities like Dhaka. The reported density figure of around 31,700 people per square kilometre further supports that the city referred to is Mumbai, confirming option A.

Why Other Options Are Wrong:
New Delhi is densely populated but is not listed with this specific figure and ranking as second in the world, so option B is incorrect.
Kolkata has a significant population density but was not the city ranked second in the world at the mentioned density, making option C wrong.
Hyderabad is a major city but has lower density compared to Mumbai and does not match the cited ranking, so option D is incorrect.

Common Pitfalls:
Candidates may confuse population size with population density, assuming that any large city might hold this rank. Another pitfall is mixing up different global lists and years. Remembering that Mumbai is often highlighted for extreme crowding and high density helps to choose correctly even when similar cities are listed as distractors.

Final Answer:
The Indian city ranked as the second most densely populated in the world was Mumbai.