Correct Answer: B

Rationale: The correct answer is B: K-antigen. H. Influenzae types are classified based on their capsular polysaccharides, which are known as K-antigens. The K-antigen is a major virulence factor and plays a crucial role in the pathogenicity of H. Influenzae. The other options (A, C, D) are not used to classify H. Influenzae types. Vi-antigen is related to Salmonella serotyping, O-antigen is characteristic of gram-negative bacteria such as Escherichia coli and Salmonella, and H-antigen is typically associated with flagellar antigens of bacteria like Salmonella and E. coli.

Correct Answer: C

Rationale: The correct answer is C: Mumps. Group II diseases are vaccine-preventable diseases that are communicable and can cause outbreaks. Mumps fits this criteria as it is preventable through vaccination, easily transmitted through respiratory droplets, and can lead to outbreaks in communities. Anthrax (A) is a zoonotic disease, Lyme disease (B) is transmitted by ticks, and Smallpox (D) has been eradicated.

Correct Answer: C

Rationale: Rationale: 1. Bacillus anthracis is a spore-forming bacterium that can survive for decades in the soil. 2. The spores are resistant to harsh conditions and can remain dormant for long periods. 3. This resilience allows Bacillus anthracis to persist in the old cattle burial ground for over 50 years. 4. Mycobacterium bovis, Brucella abortus, and Francisella tularensis are not known for long-term survival in soil. Summary: - Mycobacterium bovis, Brucella abortus, and Francisella tularensis do not have the spore-forming ability. - Mycobacterium bovis causes tuberculosis in cattle. - Brucella abortus causes brucellosis in cattle. - Francisella tularensis causes tularemia in animals and humans.

Correct Answer: C

Rationale: The correct answer is C, as Gram-negative bacteria have a cell wall containing lipopolysaccharides. This outer membrane structure is unique to Gram-negative bacteria and plays a critical role in pathogenicity and immune response. Teichoic acid (choice A) is found in Gram-positive bacteria. The cell wall of Gram-negative bacteria is thinner than that of Gram-positive bacteria (choice B). The cell wall of Gram-negative bacteria is not composed entirely of peptidoglycan (choice D), as it also contains other components like lipopolysaccharides.

Correct Answer: A

Rationale: Rationale: Metronidazole is the drug of choice for treating lambliosis due to its effectiveness against Giardia lamblia, the parasite causing the infection. Metronidazole works by disrupting the DNA structure of the parasite, leading to its death. Erythromycin (choice B) is not effective against Giardia lamblia. Monomycin (choice C) and Chingamin (choice D) are not commonly used for treating lambliosis. Therefore, choice A, Metronidazole, is the correct medication for this patient.