The first alternative is correct (A).
Russia was already a great territory when Peter the Great ascended to power. However, the country did not have easy access to the sea and Pedro wanted to change that. In 1700, he led a Russian war against Sweden, which controlled the Baltic Sea. This conflict became known as the Great Northern War. During the conflict, Peter built a new capital, St. Petersburg, on lands that had been taken from the Swedes. Russia ended up winning the war in 1721.