This is the name for 18th century trade between West Africa, the West Indies, North America and europe

triangular trade

Explanation:

For the British slave traders it was a three-legged journey called the 'triangular trade': West African slaves were exchanged for trade goods such as brandy and guns. Slaves were then taken via the 'Middle Passage' across the Atlantic for sale in the West Indies and North America.

the answer is

a) revise existing treaties

b) do away with political alliances

c) prevent the spread of communism

d) bring an end to european colonization

the main goal of the southeast asia treaty organization was to prevent the spread of communism in southeast asia.