Which excerpt from "Marian Anderson Sings" best supports the idea that Anderson witnessed a positive shift in attitude of many Americans towards African Americans? "'I had a feeling that a great wave of good will poured out from these people, almost engulfing me.'"

"To sing at the Lincoln Memorial would be a bold political statement."

"Of all who gathered that day at the Lincoln Memorial, no one could have been moved more deeply than Marian Anderson."

"The First Lady, Eleanor Roosevelt, even resigned from the DAR in protest, making front-page headlines all over the country."