A map of North America. A key shows 4 main climate zones and their subzones by color. Heading 1: Dark purple = Tropical rainforest. Light purple = Tropical savanna. Heading 2: Yellow = Steppe. Tan = Desert. Heading 3: Dark green = Marine west coast. Green = Mediterranean. Aqua = Humid subtropical. Orange = Humid continental. Heading 4: Light gray = Subarctic. Gray = Tundra. Brown = Highlands. Hawaii and southern Florida are purple. Southeast and south central United States are aqua. Northeast and north central United States and part of southern Canada are orange. Western United States are mainly yellow and brown with some tan, green, and dark green near the coast. Northern Canada is dark gray. Central Canada is gray.

Use your knowledge of the climate zones of the United States and Canada to interpret the map above.
Look at the map key. What is the correct heading for zone four (4)?
A.
Tropical
B.
High-latitude
C.
Dry
D.
Midlatitude