**Core Concept**
Heart failure cells are a histopathological hallmark of severe heart failure, characterized by the presence of hemosiderin-laden macrophages within the lungs. This phenomenon is a result of pulmonary congestion leading to capillary rupture and subsequent iron deposition.

**Why the Correct Answer is Right**
The formation of heart failure cells is a consequence of the increased hydrostatic pressure in the pulmonary capillaries due to left ventricular failure. This high pressure causes capillary rupture, leading to the leakage of red blood cells into the alveolar space. The macrophages then phagocytose the extravasated red blood cells, resulting in the accumulation of hemosiderin, which is visible upon histological examination. The presence of hemosiderin-laden macrophages in the lungs is a specific indicator of severe heart failure.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not directly relate to the histopathological changes seen in heart failure.

**Option B:** This option is incorrect as it refers to a different pathological condition, not directly related to heart failure cells.

**Option C:** This option is incorrect as it is a treatment for heart failure, not a characteristic of the condition.

**Clinical Pearl / High-Yield Fact**
Heart failure cells are often seen in conjunction with other histopathological changes, such as pulmonary edema and fibrosis, which are indicative of severe heart failure. The presence of heart failure cells should prompt the clinician to investigate the underlying cause of the heart failure and to consider aggressive management strategies.

**Correct Answer: C. Pulmonary congestion**