According to the passage, which of the following statements about the "cultural centers" is true? A. They were the venue where many later leaders of the Chicano civil rights movement first became politically active. B. Though later widespread, they originated in San Francisco area. C. Springing up in a number of communities, they initially had largely a political goals centered on art instruction. D. They constituted the nucleus from which the Chicano civil rights movement originated. E. Founded by artists, they provided support for the Chicano civil rights movement.