Answer:
Use concealed propoganda.
Explanation:
Hiding the true meaning of your propoganda and advertisements can change someone's opinion on something without them even knowing what they're changing it to.
A because NYC is there with over 8 million people alone
Well, it would probably have to do with the research on our own opinions, so it would be A).
The the third one because of the sentence
There was a series of laws and amendments passed to give them their rights, and example would be:
The right to vote
The destruction of man being enslaved do to color of skin
Etc.
But of course this stuff kept going until the late 1800`s, but finally died down
