Historically, most FDI has been directed at the $\_\_\_\_\_$ nations of the world as firms based in advanced countries invested in $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.$

Question $13$Select one:

a$.$

Underdeveloped, each other's markets

b$.$

Developed, each other's markets

c$.$

Developed, underdeveloped countries

d$.$

Underdeveloped, underdeveloped countries