In thermodynamics, an idealized blackbody is an object that reflects zero incident electromagnetic radiation, absorbing all such radiation instead and consequently warming up. The blackbody emits just as much energy per unit time as it absorbs; the electromagnetic spectrum of the emitted energy, however, is completely determined by the temperature of the blackbody and by no other properties thereof, such as material composition or structure. In contrast, reflected radiation undergoes no fundamental change in its original spectral characteristics, other than a possible Doppler shift created by the motion of the reflector relative to an observer. Researchers have recently discovered that a microscopic "forest" of vertically aligned single-wall carbon nanotubes of varying heights applied to a surface has extremely low reflectance across a wide range of wavelengths of visible light, the closest scientists have come thus far to creating a perfectly dark material.

Which sentence in the passage states the variables that define the electromagnetic spectrum of a blackbody?





Consider each of the answer choices separately and indicate all that apply.

Which of the following can be properly inferred from the passage?

A. An object that reflects incident electromagnetic radiation is not an idealized blackbody.
B. Reflected radiation always exactly matches the spectral characteristics of the original incident radiation.
C. A microscopic "forest" of vertically aligned single-wall carbon nanotubes of varying heights applied to a surface will absorb all incident electromagnetic radiation.