Large inequalities in wealth always threaten the viability of true democracy, since wealth is the basis of political ...

I noticed that one of the possible answers was immediately disregarded because of the term "sometimes". The explanation was that the original question did not have any quantifiers in it such as this one. Maybe this was explained in earlier videos, but it seems like an important concept that I do not recall. I am hoping to get a solid understanding of it because I figure it is a great way to quickly dismiss incorrect answers. Thanks in advance!