One astronomical unit is equal to the distance from Earth to the Sun. The second option among all the options given in the question is the correct option. The distance as calculated in the year 2012 by the International Astronomical Union was equal to 149597870700 meters. Astronomers like to use this unit for measuring the distances between planets and other solar bodies.
Finland has the most islands, with an estimated total 221,800.
Hope this helps.
The area just north of Lake Baikal is called the Irkutsk Oblast, where the city of Irkutsk is located (in Siberia).
