**Core Concept**
Goodpasture’s syndrome is an autoimmune disease characterized by autoantibodies targeting the basement membrane of glomeruli and alveoli, leading to severe pulmonary and renal involvement. It primarily presents as rapidly progressive glomerulonephritis and diffuse alveolar hemorrhage due to immune-mediated damage.

**Why the Correct Answer is Right**
Goodpasture’s syndrome is defined by antibodies against the non-collagenous domain of type IV collagen in the basement membrane, causing damage in both glomeruli and alveolar walls. This leads to **glomerulonephritis** (A) and **diffuse alveolar hemorrhage** (C). The presence of **antibodies to basement membrane** (D) is a hallmark diagnostic feature. However, **leucocytoclastic vasculitis** (B) is not a feature of Goodpasture’s syndrome; it is more commonly seen in conditions like systemic vasculitis or infections, not in this specific autoimmune disease.

**Why Each Wrong Option is Incorrect**
Option A: Glomerulonephritis is a hallmark of Goodpasture’s syndrome due to immune-mediated injury to glomerular basement membranes.
Option C: Diffuse alveolar hemorrhage occurs in the lungs due to antibody-mediated damage to alveolar basement membranes, leading to bloody sputum and hypoxemia.
Option D: Antibodies against type IV collagen in basement membranes are pathognomonic for Goodpasture’s syndrome and are detectable in serum or urine.

**Clinical Pearl / High-Yield Fact**
Remember: Goodpasture’s syndrome is a rare, life-threatening autoimmune disease with **antibodies against type IV collagen**, leading to **rapidly progressive renal failure** and **pulmonary hemorrhage**. Early diagnosis and prompt immunosuppressive therapy (e.g., plasma exchange, corticosteroids) are critical to survival.

✓ Correct Answer: B. Leucocytoclastic Vasculitis