Two Physicists, One in Australia, the Other in the United

Two physicists, one in Australia, the other in the United States, find that each has constructed an ideal blackbody in the laboratory. The two blackbodies are made from very different materials. Without conducting tests, they know that the radiation emitted by these two objects will be:

A) different because the amount of light falling on them is likely to be different in the two laboratories.
B) identical to each other if the blackbodies have the same size, even if their temperatures are different.
C) different from each other because of the difference in materials.
D) identical to each other if the blackbodies are at the same temperature but not otherwise.