Read this passage from "marian anderson sings":   "anderson's manager wrote to make arrangements. the date he wanted was already taken, he was told. he suggested other dates in april. he was told that those were taken, too. in fact, no dates were available at all."  why does the author of the story include this passage?   a. to show that constitution hall is a popular venue for singers in the month of april   b. to show that anderson was being discriminated against for her race   c. to show how difficult and competitive the music business can be   d. to show that anderson was not popular enough to be able to reserve constitution hall