The correct option is B Vatican city Vatican city,
The state of Vatican City is the smallest country in Europe and as well as in the world both by size and population with an area of around 0.17 square miles. The country is not formally self-governing, and it is governed by the Holy See. The population was estimated at 1,000 in 2015. The city was established through the Lateran treaty signed on February 11, 1929, between the Holy See and Italy. Italian is the official language of the Vatican. Vatican City is located at the Vatican Mount, and so the name was derived from the mountain. The government of Vatican City is an absolute elective monarchy with the power being exercised by the head of the Roman Catholic Church, the Pope.