Answer:
A. The Eastern European Plain
B. The Russian Lowlands
Step-by-step explanation:
Western geographers refer to the Eastern extension of the Northern European Plain as the "Eastern European Plain", while Russian geographers refer to it as "the Russian Plain". In Russia itself, people sometimes colloquially call it "the Russian Lowlands".
The Eastern European Plain is very large, and comprises the Baltics, the Kaliningrad Oblast, northeastern Poland, Belarus, most of Ukraine, moldova, and the totality of European Russia except of the the southermost part of it (the Caucasus area), and the Karelian Peninsula, including the Oblast of Murmansk.