Which excerpt from the passage best states the authors' claim?

"The English were getting richer because Africans were being turned into property."
". . . while that link gave the English a stake in slavery, it also gave the antislavery forces an opportunity."
"They created the most effective public relations campaign in history, inventing techniques that we use to this day."
". . . Clarkson and others organized what we would call a boycott of 'the blood-sweetened beverage.