If between wavelength `lambda` and`lambda + dlambda`, `e_(lambda)` and `a_(lambda)` be the emissive and absorptive powers of a body and `E_(lambda)` be the emissive power of a perfectly black body, then according to Kirchoff's law, which is true

Options

A. `e_(lambda)=a_(lambda)=E_(lambda)`
B. `e_(lambda)E_(lambda)=a_(lambda)`
C. `e_(lambda)=a_(lambda)E_(lambda)`
D. `e_(lambda)a_(lambda)E_(lambda)="constant"`