Andre Gunder Frank's Classic Concept of the "Development of Underdevelopment

Andre Gunder Frank's classic concept of the "development of underdevelopment" suggests that:

A) development and underdevelopment are related as two sides of the same coin
B) the development of the advanced industrial countries has been greatly facilitated by the exploitation of the rest of the world
C) Wallerstein's concepts of core and periphery are essential for understanding the problem of underdevelopment
D) all of these