**Core Concept**
Scotochromogens are a type of mycobacteria that produce pigment in the presence of light. This characteristic is used to differentiate them from non-chromogenic and photochromogenic species. The term 'scotochromogen' comes from the Greek words 'skotos,' meaning darkness, and 'chroma,' meaning color.

**Why the Correct Answer is Right**
The correct answer is a type of mycobacteria that produces pigment in the dark, without the need for light. This characteristic is due to the enzyme mycosine, which is responsible for the production of the pigment. Mycosine acts on the substrate to produce the pigment, which is then accumulated within the bacterial cells. The pigment production in scotochromogens is a result of the metabolic activity of the bacteria, and it is not dependent on the presence of light.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it is a type of mycobacteria that produces pigment in the presence of light, which is characteristic of photochromogens, not scotochromogens.
* **Option B:** This option is incorrect because it is a type of mycobacteria that does not produce pigment, which is characteristic of non-chromogenic species.
* **Option D:** This option is incorrect because it is a type of mycobacteria that is not commonly classified as scotochromogen.

**Clinical Pearl / High-Yield Fact**
Scotochromogens are often found in the environment and can cause disease in humans, especially in immunocompromised individuals. They can be differentiated from other mycobacteria species based on their ability to produce pigment in the dark.

**Correct Answer: C. M. gordonae**