C is the most reasonable place. A has two good choices, but swamp land isn't suitable for agriculture. B has the Alluvial plains which are not the best. D has the Tundra which is horrible for agriculture.
Most of europe was occupied by germany, poland was occupied by nazis, switzerland sweden and spain remained neutral, great britain and the soviet union were allies held areas, you can search up a map of europe in 1942 more more detail hope this helped
