The pink city of India is-
Option 4 is the right answer.
Jaipur has been popularized with the name of Pink City because of the color of the stone exclusively used for the construction of all the structures. Anyone who has witnessed the city can substantiate the fact that all the buildings of Jaipur are pink in color. The pink color has its own history. In 1876, the Prince of Wales and Queen Victoria visited India on a tour. Since pink denotes the color of hospitality, Maharaja Ram Singh of Jaipur painted the whole city pink in color to welcome the guests. The tradition has been sincerely followed by the residents who are now, by law, compelled to maintain the pink color.