Final answer:
The Yenisei River separates western from eastern Siberia. It is the largest river system flowing to the Arctic Ocean and defines the western edge of the Central Siberian Plateau.
Step-by-step explanation:
The river that separates western from eastern Siberia is the Yenisei River. The Yenisei River is the largest river system flowing to the Arctic Ocean and it defines the western edge of the Central Siberian Plateau. Options A)The Ob River, C)The Lena River, and D)The Kolyma River, while they are significant rivers in Siberia, they do not serve as the demarcation line between western and eastern Siberia like the Yenisei River does.
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