When a mycobacterium is described as a scotochromogen, this means that colonies of the organism on solid media are:
(a) Non-pigmented whether grown in dark or light
(b) Pigmented whether grown in dark or light
(c) Non-pigmented when grown in the dark, but pigmented after exposure to light
(d) Pigmented when grown in the dark, but the pigment disappears after exposure to light
B. Pigmented whether grown in dark or light
A scotochromogen is a type of mycobacterium that produces pigment regardless of whether it is grown in the dark or light. This characteristic is used in the identification and classification of mycobacterial species.