## Core Concept
Lichenoid reactions are drug-induced eruptions that clinically and histologically resemble lichen planus. These reactions are considered type IV hypersensitivity reactions, involving cell-mediated immunity. Various medications have been implicated in triggering lichenoid reactions.

## Why the Correct Answer is Right
The correct answer, **D. All of the above**, indicates that multiple classes of drugs can cause lichenoid reactions.
- **A. NSAIDs (Nonsteroidal Anti-Inflammatory Drugs)**: These can cause lichenoid reactions, although less commonly.
- **B. Antihypertensives**: Certain antihypertensive drugs, especially beta-blockers and diuretics, have been associated with lichenoid eruptions.
- **C. Antidiabetics**: Some oral hypoglycemic agents have been implicated in drug-induced lichenoid reactions.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it only lists NSAIDs, which is not an exhaustive list of drugs causing lichenoid reactions.
- **Option B:** This option is incorrect because it only mentions antihypertensives, omitting other drug classes like antidiabetics and NSAIDs.
- **Option C:** This option is incorrect as it only refers to antidiabetics, neglecting other implicated drugs.

## Clinical Pearl / High-Yield Fact
A key point to remember is that drug-induced lichenoid reactions often resolve within weeks to months after withdrawal of the offending agent. The reaction can sometimes be severe enough to warrant systemic corticosteroids.

## Correct Answer Line
**Correct Answer: D. All of the above.**