According to the historical viewpoint expressed in the idea of the long twentieth century which came first?

The choices are;
a. rivalries 
b. alliances
c. mercantilism
d. industrialization.

The Long Twentieth Century was written by Giovanni Arrighi,  The answer is c. mercantilism

Mercantilism was the onset ground for the territorial expansion of Europeans it created the capitalist mode of thinking. In relation to this, Arrighi divided the period of the Long Twentieth Century into three phases. First, the financial expansion that ended the old British economic system and was replaced by the US new economic system during the late 19th century till the early 20th century.  The second was material expansion in the mid 19th century; the last phase was the current and future of these developments. 

The answer is b.african american abolitionists emphasized legal and social equality