_____ was the first urban settlement to reach one million population in world.

London, (1810)

The correct answer is Option (2) → London, (1810).

Rapid urban growth is a recent phenomenon. Until recent times, few settlements reached the population size of more than a few thousand inhabitants. The first urban settlement to reach a population of one million was the city of London by around. A.D. 1810 By 1982 approximately 175 cities in the world had crossed the one million population mark. Presently 54 per cent of the world’s population lives in urban settlements compared to only 3 per cent in the year 1800.