**Core Concept**
Kerley B lines are short, horizontal lines at the lung periphery, seen on chest radiographs in patients with pulmonary edema. They represent interstitial edema, which is a hallmark of congestive heart failure.

**Why the Correct Answer is Right**
Kerley B lines are caused by fluid accumulation in the interstitial spaces of the lung due to increased hydrostatic pressure. This is often a result of left-sided heart failure, where the left ventricle fails to pump blood effectively, leading to increased pressure in the pulmonary capillaries. The fluid then leaks into the interstitial spaces, causing Kerley B lines to appear on chest radiographs.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because Kerley B lines are not typically seen in patients with restrictive lung disease, such as pulmonary fibrosis. In restrictive lung disease, the lung tissue itself is stiffer and less compliant, leading to a different set of radiographic findings.

**Option B:**
This option is incorrect because Kerley B lines are not characteristic of pleural effusions. Pleural effusions are collections of fluid in the pleural space, which can be seen as a separate entity on chest radiographs.

**Option C:**
This option is incorrect because Kerley B lines are not typically seen in patients with chronic obstructive pulmonary disease (COPD). COPD is characterized by airflow limitation and is associated with a different set of radiographic findings, such as hyperinflation and bullae.

**Clinical Pearl / High-Yield Fact**
Kerley B lines are a classic radiographic finding in patients with congestive heart failure. They are a sign of interstitial edema and should prompt a thorough evaluation of the patient's cardiac function.

**Correct Answer: D.**