Sentence Correction (SC) | Re: QOTD: However much United States voters

Isn't HOWEVER an Independent Marker ?
so how is it in option A , the sentence before comma is used as a subordinating clause ?
or is it that since here we have "however much" , it is not an independent clause ?
And if no, then what's the correct usage of however ?
sayantanc2k

However much United States voters may agree that there is waste in government and that the government as a whole spends beyond its means, it is difficult to find broad support for a movement toward