Answer:
Option: Rich soil and fairly mild climate.
Explanation:
Russia's first civilization grew in a fertile land (Ukraine) which helped people to survive and flourish. The black soil in Ukraine provided fertile land with rich in humus. Slavic peoples were the first to migrate into the area of Ukraine. Russia civilization began by King Rurik of the Rus in 862. The Rus captured the city of Kiev and established the kingdom of the Kievan Rus. The Kievan Rus reached its peak under Vladimir and Yaroslav I during the 10th and 11th century.
