The correct answer is B.
A democratic method means by people as opposed to for people.
The way a democratic method works is by election, where the voice and opinion of the majority of people is heard and seen. Election is the fairest way to choose a person of authority because only the best candidate wins.
To win a position of authority, the candidate must be considered best suited by the majority of people. To ensure that it happens, an election is needed. Each candidate has equal chances of winning but only the one considered the best suited does win.
The voting by majority ensures that the winner represents the idea of a large group of people, and that his election to this position happened in a fair, unforced manner.