Which war began the modern era?

a)world war i
b)the american civil war
c)world war ii
d)the chinese civi

A) World War I

Explanation:

The war that began the modern era was World War 1.  

World War 1 was the first great war of the century. This was a global event that initiated on July 1914 until November, 1918.

The answer A. World War I. Thank me later

slavery, abortion, donald trump, gay marriage, racial rights, immigration  

explanation:

anything that has been broth up to the supreme court is something of grate political divide   so just look as court cases