Open Question: What is the most likely relationship of extensive material inequality to democracy?

From Yahoo Answers

a. Extensive material inequality may undermine the possibilities for political equality because those with financial resources have greater access to public officials.b.Material inequality may increase the possibilities for political equality by creating incentives for political participation.c. Material inequality leads to public unrest, which will create a more democratic system as the majority begins to demand more protection.d. The degree of material inequality has no relationship to democracy.