Hi - I’m not entirely understanding the logic behind the sentence. I figured out that there’s a contrast with “even after”. The second part contained the word skeptical which indicated a negative to me. once I figured that out, I knew the first blank had to be something positive.
My thinking was that Even after proposals against the inclusion of popular sovereignty were included, major figures in the human disciplines remained skeptical about the proposal to extend suffrage to the masses.
First you must know that here “popular sovereignty” is a synonym for “suffrage to the masses”. I would simplify this to “democracy.”
Then you get something like: “Even after _____ against the ______ of democracy were included, people remained skeptical about introducing even more democracy.”
So people are uncomfortable with the idea of more democracy EVEN THOUGH (something).
They’re uncomfortable with more democracy even though there have been safeguards against too much democracy. So B.