You are answering a USMLE-style medical question. Question: A 42-year-old man is brought to the emergency department because of a 2-day history of dyspnea, chest pain, and hemoptysis that were preceded by 4 days of myalgia and a low-grade fever. He is currently visiting the United States as a tourist from Turkey, where he works at a factory that processes sheep wool and hide. An x-ray of the chest shows widening of the mediastinum. A sputum culture grows gram-positive rods in gray colonies that have irregular margins with wavy projections on microscopy. Which of the following virulence factors of the causal organism increased its survival in host tissue? Options: A) Glutamate capsule B) Toxin B C) IgA protease D) Sulfatides Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.