<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 39-year-old man comes to the emergency department because of a 2-day history of fever, chills, dyspnea, and a non-bloody productive cough. He was diagnosed with HIV infection 4 years ago and has been on highly active antiretroviral therapy since then. His temperature is 38.8C 101.8F. Examination shows crackles over the left lower lung base. His CD4 T-lymphocyte count is 520mm3 N 500. An x-ray of the chest shows an infiltrate in the left lower lobe. Sputum cultures grow colonies with a narrow zone of green hemolysis without clearing on blood agar. The most likely causal pathogen of this patients condition produces which of the following virulence factors?? A: M protein, B: Lipopolysaccharide, C: Type III secretion system, D: Polysaccharide capsule, E: Protein A,  <response>: This is a medical question asking about the most likely causal pathogen in a patient with HIV who presents with fever, chills, dyspnea, productive cough, and a lung infiltrate. The description of colonies growing on blood agar plates with narrow zones of beta-hemolysis suggests streptococcus pneumoniae infection. S. pneumoniae is an encapsulated bacterium, so the virulence factor that best matches is a polysaccharide capsule.D: Polysaccharide capsule 