Analyze the map below and answer the question that follows.
A world map. The key show the following: Grey = Dry Climate, Blue = Cold Climate, Green = Humid/not vulnerable, White = Ice/glacier. Most of central and eastern China is circled and shaded green.
Image courtesy of the USDA

Part of China is circled in black on the map above. Based on the map key, why is southeastern China not at risk of desertification?
A.
Southeastern China is colored in grey, which means it already is a desert.
B.
Southeastern China is colored in blue, which means it is cold year-round.
C.
Southeastern China is colored in green, which means it has a humid climate that regulates environmental and ecological changes, preventing desertification.
D.
Southeastern China is colored in white, which means it is mostly ice year-round; icy climates have so much rain that it’s impossible for the land to become dry.