A．The experiments failed to a connection between different colors.
B．The experiments showed useful connections between color and light.
C．The experiments provided valuable information about the relationships between colors.
D．The experiments were not useful until modern psychologists reinterpreted them.

A．He felt they represented natural light at different times of the day.
B．He noticed that they were the favorite colors of Romantic painters.
C．He performed several scientific experiments that suggested those colors.
D．He read a book by Goethe and agreed with Goethe's choices of colors.

A．Many people have proposed theories about primary colors.
B．Goethe discovered the primary colors by accident.
C．Goethe probably developed the primary color theory before reading Runge's letter.
D．Goethe may have been influenced by Runge's ideas about primary colors.