**Core Concept**
The question is testing the understanding of the radiological signs associated with cardiac conditions, specifically the relationship between cardiac silhouette and lung fields on chest X-rays. A "globular heart" refers to an enlarged cardiac silhouette, while "plethoric lung fields" indicate increased vascular markings.

**Why the Correct Answer is Right**
The globular heart with plethoric lung fields is characteristic of **congestive heart failure (CHF)**. In CHF, the heart is unable to pump blood efficiently, leading to fluid accumulation and congestion in the lungs and peripheral tissues. The increased blood volume in the lungs results in increased vascular markings, giving a plethoric appearance. The globular heart shape is due to the enlargement of the heart as it becomes overloaded with fluid.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided.
* **Option B:** This option is not provided.
* **Option C:** This option is not provided.
* **Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the cardiac silhouette can be altered by various conditions, including CHF, pericardial effusion, and cardiomegaly due to other causes. A globular heart with plethoric lung fields is a classic radiographic sign of CHF, but it's crucial to consider the clinical context and other diagnostic findings to make an accurate diagnosis.

**Correct Answer:** D.