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

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

A.            p = 0, x = 0 and a = 1

B.            p = 0, x = 1 and a = 0

C.            x – 0, a + p = 1

D.            a=0,x + p= 1

Answer: x – 0, a + p = 1