Part A Evaluate these statements about Koch's postulates, which are used to establish a causative link between a specific microbe and a specific disease. Which of them are true? Select all that apply. O The microbe must be present in individuals suffering from the disease and absent from healthy individuals. O The microbe does not have to be isolated from the experimental animal as long as the disease is present. O If organisms from the pure culture are injected into a healthy experimental animal, the disease symptoms should appear. O The microbe must be isolated and grown in pure culture.