Answer:
This answer is really opinion based, but I would go with the latter being wealth.
Step-by-step explanation:
The reason I chose wealth is because equality of income is definitely not a necessity , seeing as democracy does exist where income is not equal. At the same time though, would lack of wealth prevent democracy? I would disagree but seeing as there are two options, wealth makes more sense just due tot he absurdity of the other option. Why would everybody need to have equal income for democracy to work? Isn't democracy useful for those who lack the same situation as others. Democracy benefits the lower income population if there is more of them then the wealthy.