## Core Concept
Pulmonary venous hypertension, often a result of left heart failure or mitral valve disease, leads to a backlog of blood in the pulmonary veins and capillaries. This condition increases the pressure in the pulmonary circulation and can cause various clinical and radiological features. Understanding these features is crucial for diagnosing and managing patients with pulmonary venous hypertension.

## Why the Correct Answer is Right
The correct answer, , typically represents a feature that is not associated with pulmonary venous hypertension. Common features of pulmonary venous hypertension include:
- Pulmonary edema: Fluid accumulation in the lungs due to increased pressure.
- Pleural effusion: Fluid accumulation in the pleural space.
- Kerley B lines: Short, horizontal lines at the lung periphery representing interstitial edema.
- Cephalization: Increased vascular markings in the upper lung fields compared to the lower fields.

## Why Each Wrong Option is Incorrect
- **Option A:** If option A describes a feature commonly seen in pulmonary venous hypertension, such as pulmonary edema or pleural effusion, it would be incorrect because the question asks for "A/E" (all except).
- **Option B:** Similarly, if option B represents a characteristic feature like Kerley B lines or cephalization, it would be wrong for the same reason.
- **Option D:** If option D is another feature associated with pulmonary venous hypertension, it would also be incorrect.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that pulmonary venous hypertension often presents with signs of left heart failure, such as orthopnea, paroxysmal nocturnal dyspnea, and S3 heart sound. Radiographic findings like cardiomegaly and pulmonary edema are also common.

## Correct Answer Line
**Correct Answer: D. Increased pulmonary artery diameter**