<prompt> Which of the following is true regarding anthrax -a M Fadyean reaction shows capsule b Humans are usually resistant to infectionc Less than 100 spores can cause pulmonary infectiond Gram stain shows organism with bulging sporese Sputum microscopy helps in diagnosisabceabcdacdeabde  <response>: Option b: Greenwood 16e p226 says Humans are relatively resistant to infection with B anthracisOption c: Harrison 17e p1344 and 18e p1769 says While an LD50 of 10,000 spores is a generally accepted number for anthrax it has also been suggested that as few as one to three spores may be adequate to cause disease in some settings.Option d: Gram stain shows organism with non bulging spores.Bulging spores are seen for ClostridiumOption e: Microscopy of the sample like lesion, blood, sputum reveals gram-positive bacilli in chain.Ref: Apurba Sastrys Essentials of Medical Microbiology p250-53, Ananthanarayan 9e p247-48, 8e p243 