Black tongue and black teeth are seen in abuse of
**Core Concept**
The question is testing the knowledge of a specific condition associated with substance abuse, which affects the oral cavity. This condition is characterized by discoloration of the tongue and teeth, resulting from an accumulation of a particular substance.
**Why the Correct Answer is Right**
The correct answer is related to the abuse of a substance that leads to the production of a compound causing the discoloration. The enzyme responsible for this reaction is a type of oxidase, specifically a monamine oxidase. The accumulation of this compound is due to the breakdown of a specific amino acid by this enzyme, resulting in a dark-colored pigment. The substance responsible for this abuse is a stimulant, often used in combination with other substances.
**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because the substance associated with it is not typically linked to the production of a dark-colored pigment in the oral cavity.
**Option B:**
This option is incorrect because the substance associated with it is not typically associated with the breakdown of an amino acid by a monamine oxidase enzyme.
**Option C:**
This option is incorrect because the substance associated with it is not typically linked to the production of a dark-colored pigment in the oral cavity.
**Option D:**
This option is incorrect because the substance associated with it is not typically associated with the breakdown of an amino acid by a monamine oxidase enzyme.
**Clinical Pearl / High-Yield Fact**
Remember that the substance associated with this condition is often used in combination with other substances, leading to a range of systemic effects. The condition is also associated with poor oral hygiene and other health complications.
**Correct Answer: C. Cocaine. The abuse of cocaine leads to the accumulation of a dark-colored pigment in the oral cavity, resulting in black tongue and black teeth.**