Film Art Argues That the Search for the Meaning of "Rosebud

Film Art argues that the search for the meaning of "Rosebud" in Citizen Kane is more than a gimmick because

A) Thompson's discovery of "Rosebud" is what permits the narrative to achieve complete closure.
B) the "Rosebud" motif creates parallelisms among all the flashbacks.
C) the search provides a cause that motivates an investigation into character traits.
D) "Rosebud" provides vital motivation about why Kane's mother sent him to live with Thatcher.