Analyze the map below and answer the question that follows.
A topographic map of Northwestern Russia. Areas on the map are circled and labeled 1, 2, 3, and 4. 1 is a mountain range. 2 is a flat area. 3 is a highland area. 4 is a plateau.
Image by Natural Earth
All of the regions on the map above are part of Siberia except __________.
A.
region 1
B.
region 2
C.
region 3
D.
region 4