- A Salmonella typhi
- B Vibrio cholerae
- C Entamoeba histolytica
- D Plasmodium vivax
Correct answer: A. Salmonella typhi
Explanation: Typhoid fever is caused by Salmonella typhi, a gram-negative bacterium. It spreads through contaminated food and water. Diagnosis: Widal test. Treatment: antibiotics (ciprofloxacin, azithromycin).
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.