The correct option is
B Typhoid
The correct option is B.
Explanation for correct option:
- The Widal test is a serological test for the diagnosis of typhoid fever.
- Typhoid is caused by the bacterium Salmonella typhii.
- This bacteria is combined with serum containing antibodies from the infected persons.
- A positive test indicates a high titer of antigen for the specific disease.
Explanation for incorrect options:
Option A:
- Malaria is an infection caused by Plasmodium.
- Hence, will not give antibody-antigen interaction.
Option C:
- Pneumonia is caused by Streptococcus pneumonia.
- The specific antigen does not test positive for the Widal test.
Option D:
- Jaundice occurs due to metabolic dysfunction of the liver, gall bladder, or pancreas.
- Hence, no antigen-antibody interaction.
Final Answer: The Widal test is to confirm typhoid.