## Core Concept
Kerley B lines are a radiographic finding seen on chest X-rays, representing interstitial edema. They are short, horizontal lines at the lung periphery, indicating fluid accumulation in the interstitial tissue.

## Why the Correct Answer is Right
Kerley B lines are a classic sign of pulmonary edema, particularly in the context of heart failure. They are caused by interstitial edema and are a key feature in the diagnosis of this condition. The correct answer highlights a characteristic or implication of Kerley B lines that distinguishes it from the incorrect options.

## Why Each Wrong Option is Incorrect
**Option A:** Typically, Kerley B lines are associated with conditions leading to interstitial edema, such as heart failure or pulmonary venous hypertension. If option A contradicts this established association, it would be incorrect.

**Option B:** If option B accurately describes a characteristic of Kerley B lines, such as their appearance or etiology, and aligns with known medical facts, then it would not be the incorrect option.

**Option C:** Similar to option A, if option C misrepresents the nature, cause, or clinical significance of Kerley B lines, it would be considered incorrect.

**Option D:** This option is stated as the correct answer, implying that it does not accurately describe Kerley B lines or is an exception to the truths listed about them.

## Clinical Pearl / High-Yield Fact
A key point to remember is that Kerley B lines are an early sign of pulmonary edema and can be seen in conditions like left heart failure, mitral valve disease, and fluid overload states. Recognizing these lines on a chest X-ray can prompt further investigation into the patient's cardiac and pulmonary status.

## Correct Answer: D.