Ans. is `b' i.e., Pigmented alveolar macrophageso Hea failure cells (siderophages) are hemosiderin containing macrophages in alveoli that are seen in left ventricular failure and denote previous episodes of pulmonary edema.Left sided hea failure o The major morphological and clinical effects of LVF are due increased back pressure in pulmonary circulation and the consequences of diminished peripheral blood pressure and flow.o The extracardiac organs involved commonly are ?1. Lung (most common)2. Kidney3. BrainLungo Pressure in the pulmonary veins increases and transmitted retrogradely to capillaries and aeries. o This results in pulmonary congestion and pulmonary-edema --> Wet lung.o There is perivascular and interstitial transdate, paicularly in the interlobular septa --> responsible for kerley's `B' lines on X-rays.o Edematous fluid accumulates in alveoli.o Iron containing proteins and hemoglobin leak out from the capillaries, and are phagocytosed by macrophages and conveed to hemosiderin.o Hemosiderin - containing macrophages in the alveoli (called siderophages, or hea failure cells) denote previous episodes of pulmonary edema.o The clinical manifestations of LVF are primarily due to these changes in lungs Dysnea, ohopnea, paroxysomal nocturnal dysnea.Kidneyo Decreased cardiac output causes a reduction in renal perfusion.o If it is severe enough to impaire the excretion of nitrogenous product (BUN, Creatinine), Prerenal ARF (Prerenal azotemia) may be precipitated.Braino Reduced perfusion to brain may cause hypoxic / ischemic encephalopathy.