Why Were Countries That Focused on the Production of Raw

Why were countries that focused on the production of raw materials or primary products like rubber,guano,or coffee at a disadvantage economically to those that industrialized?

A) Non-industrialized countries were largely at the mercy of a constantly fluctuating market.
B) Countries that produced mostly raw materials were more likely to lack adequate connections to world markets.
C) Countries that produced primary products failed to keep up with education for their populations.
D) Industrialized countries often refused to buy raw materials from these countries.