The correct matching is: P–2, Q–1, R–4, S–3, which corresponds to option (D).​

Question breakdown

Column I lists four human diseases:

• P. Sleeping sickness

• Q. Chagas disease

• R. Elephantiasis

• S. Lyme disease

Column II lists five organisms:

1. Trypanosoma cruzi

2. Trypanosoma brucei

3. Borrelia burgdorferi

4. Wuchereria bancrofti

5. Rickettsia rickettsii

The task is to match each disease in Column I with its correct causal organism in Column II.

Correct matches:

• Sleeping sickness → Trypanosoma brucei (P–2)​

• Chagas disease → Trypanosoma cruzi (Q–1)​

• Elephantiasis (lymphatic filariasis) → Wuchereria bancrofti (R–4)​

• Lyme disease → Borrelia burgdorferi (S–3)​

Therefore, option (D) is correct.

Why each correct pair is right

Sleeping sickness – Trypanosoma brucei (P–2)

• Human African trypanosomiasis, commonly called sleeping sickness, is caused by the protozoan parasite Trypanosoma brucei (subspecies T. b. gambiense and T. b. rhodesiense).​

• The disease is transmitted by tsetse flies in sub‑Saharan Africa and is characterized by hemolymphatic and late meningoencephalitic stages with disturbed sleep–wake cycles.​

Chagas disease – Trypanosoma cruzi (Q–1)

• Chagas disease, or American trypanosomiasis, is caused by the flagellated protozoan Trypanosoma cruzi.​

• It is transmitted mainly by triatomine (reduviid) bugs in the Americas and can lead to chronic cardiomyopathy and megavisceral disease.​

Elephantiasis – Wuchereria bancrofti (R–4)

• Elephantiasis in this context refers to lymphatic filariasis, most commonly produced by the filarial nematode Wuchereria bancrofti.​

• Adult worms inhabit lymphatic vessels, causing chronic lymphedema and gross enlargement of limbs and genitalia, hence the term elephantiasis.​

Lyme disease – Borrelia burgdorferi (S–3)

• Lyme disease is a tick‑borne zoonosis caused by the spirochete bacterium Borrelia burgdorferi.​

• Infected Ixodes ticks transmit the organism to humans, producing stages that include erythema migrans rash, neurologic involvement and arthritis if untreated.​

Analysis of each option

Option (A): P–3; Q–1; R–4; S–5

• P–3 incorrectly links Sleeping sickness with Borrelia burgdorferi, which actually causes Lyme disease, not African trypanosomiasis.​

• S–5 incorrectly associates Lyme disease with Rickettsia rickettsii, which is the agent of Rocky Mountain spotted fever, not Lyme disease.​

• Only Q–1 (Chagas disease–T. cruzi) and R–4 (Elephantiasis–W. bancrofti) are correct, so the overall option is wrong.​

Option (B): P–1; Q–2; R–3; S–4

• P–1 wrongly matches Sleeping sickness with Trypanosoma cruzi; T. cruzi causes Chagas disease, not African sleeping sickness.​

• Q–2 wrongly matches Chagas disease with Trypanosoma brucei, which causes African trypanosomiasis, not American trypanosomiasis.​

• R–3 and S–4 are both incorrect because Borrelia burgdorferi produces Lyme disease and W. bancrofti produces lymphatic filariasis; this option swaps the two.​

Option (C): P–2; Q–4; R–1; S–3

• P–2 correctly identifies Sleeping sickness as being caused by Trypanosoma brucei.​

• However, Q–4 and R–1 are incorrect because they assign Elephantiasis to T. cruzi and Chagas disease to W. bancrofti, which contradicts the established etiologies.​

• S–3 is correct for Lyme disease, but with multiple wrong matches this option is invalid.​

Option (D): P–2; Q–1; R–4; S–3

• P–2: Sleeping sickness–T. brucei is correct for African human trypanosomiasis.​

• Q–1: Chagas disease–T. cruzi is correct for American trypanosomiasis.​

• R–4: Elephantiasis–W. bancrofti correctly represents lymphatic filariasis.​

• S–3: Lyme disease–B. burgdorferi is the standard accepted etiology.​

• Because all four matches are correct, option (D) is the right answer.

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