The answer is: B. The biography uses a chronological structure; "Marian Anderson Sings" uses flashbacks to narrate the events.
In Biography of marina Anderson, the writer make the story develop in a proper time order, so the readers would not have a clue on things that occurs in the characters' future.
In Marian Anderson Sings, the writers constantly changing on the condition that the character face in the future and turn back to the events that happen to the characters in the past.