Mills believed that centralized power in the hands of a few democracy.
a. expanded
b. hurt
c. stabilized
d.

The answer that will fill in the blank is hurt, hurt democracy. It is because when a centralized power is in the hands of a few, it could lead to disaster. It is because it is not up to the people who will decide on what should happen on the current place, it is up to the officials. This will only lead to harm for a group of people could also testify against the will of the few people who holds power and does not do what is in favor of the people.