The correct answer is C. Chicanos.
"Chicano" was originally a pejorative (negative) term for Mexican Americans, especially the ones with an immigrant backgound.
Within the Mexican Americans there was a need for a new identity, and a feeling (both from within and from outside) that they were different both from the Mexican and from other Americans.
This identity, along with a fight for better fighters' rights, was at the heart of the Chicano Movement, which began in the 1940s. Cesar Chavez was an important activist for this movement.
The white abolitionist movement in the North was led by social reformers, especially William Lloyd Garrison, founder of the American Anti-Slavery Society, and writers such as John Greenleaf Whittier and Harriet Beecher Stowe.
It was the Mayans who built an ancient civilization, in what is now Mexico and Central America. They had an incredibly advanced civilization but were overcome by European settlers.
He was an author so he contributed by writing books to acknowledge the age of enlightment of literature and... other things!
