Final answer:
Dfc, Dfd, Dwc, and Dwd are Köppen climate types that describe the characteristics of the Subarctic climate.
Step-by-step explanation:
The terms Dfc, Dfd, Dwc, and Dwd are Köppen climate types used to describe the characteristics of the Subarctic climate. The Dfc climate is characterized by cold winters and cool summers, while the Dfd climate has extremely cold winters and mild summers. The Dwc climate also has cold winters and cool summers, but with less extreme temperatures compared to Dfc. Lastly, the Dwd climate has extremely cold winters and mild summers, similar to Dfd.