Questions 18 to 20 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.
What kind of problem did the Smithsonian American Art Museum face

A．Too many works of art leave little room for written information.
B．All the interpretations have to be digital.
C．The visitors cannot access information about the works and artists.
D．They lack of videos, audio clips, additional photographs.