Concept:A perfect emitter or absorber of radiant energy is called a black body.
Explanation:A black body is an ideal surface that absorbs all radiation falling on it and reflects none.
At any given temperature, it also emits the maximum possible radiant energy.
This means a black body is both a perfect absorber and a perfect emitter of radiation.
Dull, black surfaces behave like this in real life, so they absorb and release heat quickly.
White, red, and conducting surfaces reflect more radiation and therefore absorb or emit less energy.
A true black body is an ideal object used as a standard for comparing real surfaces.
Answer:The correct option is B. black body.