The correct option is
B The Central European plains
The Central European pains,
Dnieper River, Ukrainian Dnipro, Russian Dnepr, Belarusian Dnyapro, ancient (Greek) Borysthenes, river of Europe, the fourth longest after the Volga, Danube, and Ural. It is 1,367 miles (2,200 km) in length and drains an area of about 195,000 square miles (505,000 square km).
The Dnieper rises at an elevation of about 720 feet (220 metres) in a small peat bog on the southern slope of the Valdai Hills of Russia, about 150 miles (240 km) west of Moscow, and flows in a generally southerly direction through western Russia, Belarus, and Ukraine to the Black Sea. For the first 300 miles (480 km) it passes through the Smolensk oblast (region) of Russia, first to the south and then to the west; near Orsha it turns south once more and for the next 370 miles (600 km) flows through Belarus. Finally, it flows through Ukrainian territory: south to Kiev, southeast from Kiev to Dnipropetrovsk, and then south-southwest to the Black Sea.