Answer:
Before Europeans arrived in North America, Native American groups developed into distinct and complex societies in response to the unique environments they inhabited.
Explanation:
The main root of the Cold War between these two nations United States and The Soviet Union is only mistrust. This has caused tension between these two. And the one that signifies that response to the policies of the cold war between these is the nonaligned movement and that would be option C.
assuming efficiency of each man to dig trench, in one day, for one hour is constant,

so one man, working for one hour in one day can dig 1.5 m
so 8 men, working 3 hours a day and will take, say $d$ number of days and efficiency will be constant. so,
$\frac32=\frac{220}{8\times3\times d}$
$\implies d=\frac{55}9=6.12$