The Main Problem That Physicists Had in Understanding Blackbody Radiation

Multiple Choice

The main problem that physicists had in understanding blackbody radiation before Planck's work was:

A) Blackbody radiation came from objects that were not actually black.
B) The classically predicted frequency spectrum showed an infinitely large peak at low frequencies.
C) The classically predicted frequency spectrum showed an infinitely large peak at high frequencies.
D) The classically predicted frequency spectrum had a minimum intensity rather than a maximum as observed.
E) The classically predicted frequency spectrum had a maximum intensity that decreased with temperature, rather than increasing as observed.