Why do democracies tend to fail in poor countries?

Why do democracies tend to fail in poor countries?

A) Economic growth creates a large upper class; education levels rise; people increasingly recognize their interests and express them; pluralism; the market itself teaches citizens to be government-reliant.
B) Economic growth creates a large middle class; entrepreneurship levels rise; people increasingly recognize their interests and though they rarely express them; pluralism; the market itself teaches citizens about self-reliance, pluralism, tolerance, and not expecting too much.
C) Economic growth creates a large middle class; education levels rise; the market itself teaches citizens about self-reliance, pluralism, tolerance, and not expecting too much.
D) Economic growth creates a large middle class; education levels rise; people increasingly recognize their interests and express them; pluralism; the market itself teaches citizens about self-reliance, pluralism, tolerance, and not expecting too much.

This is for my political science class.