Answer:
The answer is C.
the decline of tensions between the U.S. and the Soviet Union
Explanation:
For several years, migration has
been attributed to climate change. People back then rely on plants and wild
animals and marine life. However, periods of and cold had a great effect on the
lives and development of plants and animals. Climate changes greatly affect what
kind of plants will grow on a certain area (cold or hot area), thus, depends
what animals will be there too. People need to go where abundant food is. When
there is scarcity of food in a certain area, they are forced to move to another
place where there is enough food. People back then moved out due to intense
cold and intense heat. Where there is cold, they look for a warmer place, where
there is intense heat; they look for a better place to cool off.
