Correct Answer: C

Rationale: Step-by-step rationale: 1. The Filoviridae family includes Marburg virus and Ebola virus. 2. Both viruses are characterized by filamentous, enveloped structure. 3. They cause severe hemorrhagic fever in humans. 4. Lassa virus and lymphocytic choriomeningitis viruses belong to Arenaviridae. 5. Chikungunya virus and Sindbis virus are alphaviruses. 6. Crimean-Congo virus and Hantaan virus are bunyaviruses. 7. Therefore, the correct answer is C.

Correct Answer: A

Rationale: The correct answer is A: Ziehl-Neelsen staining method was applied. 1. Ziehl's solution is used as a primary stain in Ziehl-Neelsen staining for acid-fast organisms like Mycobacterium tuberculosis. 2. Sulfuric acid is used as a decolorizer to remove excess stain. 3. Methylene blue is not part of the Ziehl-Neelsen staining method. 4. Burri's, Gram's, and Peshkov's staining methods are not used for acid-fast staining.

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Escherichia coli is the most common bacteria causing UTIs due to its ability to colonize the urinary tract. Salmonella enterica and Neisseria gonorrhoeae are not typically associated with UTIs. Therefore, by process of elimination, since A is correct, B and C are incorrect.

Correct Answer: D

Rationale: The correct answer is D: protozoan. Babesiosis is caused by a protozoan parasite called Babesia. Protozoans are single-celled organisms that can cause various diseases in humans. Babesiosis is transmitted to humans through the bite of infected ticks. Bacteria (choice A), viruses (choice B), and helminths (choice C) are not responsible for causing babesiosis. Bacteria are typically responsible for diseases like Lyme disease, viruses for illnesses like Zika, and helminths for infections such as parasitic worms. Thus, the correct choice for the causative agent of babesiosis is a protozoan.

Correct Answer: D

Rationale: The correct answer is D, Late congenital syphilis. This is because the patient presents with Hutchinson's teeth, which are a characteristic feature of late congenital syphilis. Hutchinson's teeth are small, barrel-shaped teeth with a wider cervix and notched incisors. The patient's history of visual impairment and hearing aid use also support the diagnosis of late congenital syphilis, as these are common manifestations of this stage of the disease. Choice A, Primary syphilis, is incorrect because it typically presents with a painless sore at the site of infection, not dental abnormalities. Choice B, Early congenital syphilis, is incorrect as dental abnormalities in this stage are usually more severe, such as mulberry molars. Choice C, Neurosyphilis, is incorrect as it primarily affects the central nervous system and does not typically present with dental abnormalities.