Answer:
Option B: It withdrew from Open Door agreements with China.
Explanation:
The Open Door policy was a statement of principles initiated by the United States in 1899 and 1900. It called for protection of equal privileges for all countries trading with China and for the support of Chinese territorial and administrative integrity.
The main factor that influenced African Americans to migrate from the South to Northern cities was that they were looking for better economic opportunities.
The Great Migration, also known as the Great Northward Migration in the 20th century, happened because most black people were badly treated by many people that still expected African Americans to be slaves, and their economic conditions were quite poor.
As a result, African Americans decided to migrate to the Northern cities, where they would get many job opportunities as well as going to have a better lifestyle by not being discriminated.
The first complex civilization in mesoamerica is considered to be the olmec civilization
Answer:
a there was no competent military leaders
