Depending on the radiating properties, a body will be opaque when

A. p = 0, x = 0 and a = 1

B. p = 1, x = 0 and a = 0

C. p = 0, x = 1 and a = 0

D. x = 0, a + p = 1

Answer: Option D

Solution(By Examveda Team)

Opaque body are those body where the atoms are closely packed and the light cannot pass through. Whereas a light may or may not pass through a black body depending whether it is opaque or transparent.
Depending on the radiating properties, a body will be opaque when x = 0, a + p = 1.