Answer:
C.Vikings established the kingdom of Rus.
Step-by-step explanation:
The vikings came from Scandinavia, and settled Kiev as the capital of Rus.
These people were originally Vikings from Sweden, a large state dominating Eastern Europe during 800s. They gathered peoples in a small kingdom under King Rurik's rule.
The Varangians, as they were known throughout the rest of Europe, were active traders and raiders who contributed the first organized Russian speaking state in Kiev.
Later, the first ruler who united with East Slavic peoples was Prince Oleg, the Kingdom of Rus would later form the larger state in Europe as we know it today (corresponding to Ukraine and Russia).