In order for a physical barrier to be effective in preventing infection, the barrier must a. prevent the substance from entering the body, trap the substance when it first enters the body, or flush the substance out of the body b. destroy the substance before it enters the body, prevent the substance from reproducing, or flush the substance out of the body c. trap the substance in the body, remove the substance from the body, or prevent the substance from reproducing d. flush the substance from the body, transport the substance in the body, or destroy the substance in the body

A48-year-old male presents with an 8-day history of productive cough, subjective fevers, and malaise. he is otherwise healthy without any active medical problems. he is a social drinker of alcohol, and denies any tobacco or drug use. on physical examination, the patient is alert and oriented. his temperature is 100.4 0 f, pulse rate is 56, respiratory rate is 18, and blood pressure is 133/64. heent is within normal limits and a chest exam has diffuse expiratory wheeze with decreased sounds to the right lower lung fields. blood labs reveal wbc 14.4, hgb 11.3, plt 233, alt 65, ast 102, and po 4 2.1. a chest x-ray reveals a dense consolidation with bulging fissures. based on these findings, what is the most likely pathogen affecting this patient?