During Which of the Following Conditions Do Lake-Effect Snows Best

During which of the following conditions do lake-effect snows best develop around the Great Lakes?

A) late fall and early winter when moist, polar air sweeps in from the east
B) early spring when moist, tropical air moves over the frozen lakes
C) late fall and early winter when cold, dry, polar air moves over the relatively warm water
D) middle winter when the unseasonably warm air mass moves over the cold water