B) European countries and the United states
Tundra is the region mostly found north of the Arctic Circle.
Answer:
Mesosphere
Explanation:
The mesosphere starts at 31 miles (50 km) and extends to 53 miles (85 km) high. The top of the mesosphere, called the mesopause, is the coldest part of Earth's atmosphere, with temperatures averaging about minus 130 degrees F (minus 90 C).
<span>The study of the physical features of the earth and its atmosphere, and of human activity as it affects and is affected by these, including the distribution of populations and resources and political and economic activities</span>