From the following disease–treatment pairs, which one is correctly matched according to standard medical practice?

Introduction / Context:
Matching diseases with their correct treatments, preventive vaccines or deficiency causes is a common type of general knowledge question that checks your understanding of basic health science. This question presents several disease–treatment pairs and asks you to identify the one that is correctly matched according to standard medical knowledge and practice.

Given Data / Assumptions:

We are given pairs linking diseases with drugs, vaccines or nutrients. Diseases mentioned include scurvy, tuberculosis, tetanus, malaria and rickets. Treatments or agents listed include thiamine, ATS, BCG, chloroquine and ascorbic acid. We assume basic knowledge of which agent is used for which disease.

Concept / Approach:
Chloroquine is a classic antimalarial drug used to treat infections caused by Plasmodium species, especially in areas where resistance is low. Therefore, the pair malaria – chloroquine is correctly matched. Scurvy is caused by deficiency of vitamin C (ascorbic acid), not thiamine. Thiamine deficiency leads to beriberi. The BCG vaccine is used as a preventive measure against tuberculosis, not tetanus. Tetanus is prevented by tetanus toxoid and treated with tetanus antitoxin and antibiotics, whereas ATS (anti-tubercular serum) is not the standard term for modern TB treatment, which uses multiple antibiotics. Rickets is due to vitamin D deficiency, not vitamin C.

Step-by-Step Solution:
Step 1: Examine each pair and recall the correct association for the disease. Step 2: For scurvy, remember that it is due to vitamin C deficiency, so matching it with thiamine (vitamin B1) is wrong. Step 3: For tuberculosis, note that modern treatment uses combinations of drugs such as isoniazid, rifampicin and others, and BCG is the correct vaccine, not ATS as a standard treatment. Step 4: For tetanus, recall that prevention uses tetanus toxoid vaccine and treatment uses tetanus antitoxin, not BCG. Step 5: For malaria, recognise that chloroquine is a well known antimalarial drug, making this pair correctly matched among the options.

Verification / Alternative check:
Another way to verify is to mentally list the vitamin deficiency diseases: scurvy equals vitamin C deficiency, rickets equals vitamin D deficiency, beriberi equals thiamine deficiency and pellagra equals niacin deficiency. This instantly shows that scurvy – thiamine and rickets – ascorbic acid are both incorrect. Next, recall that BCG stands for Bacillus Calmette–Guérin, a vaccine used against tuberculosis, not tetanus. With these incorrect pairs eliminated, malaria – chloroquine remains as the only clearly correct match, confirming it as the answer.

Why Other Options Are Wrong:
Scurvy – thiamine is wrong because scurvy arises from lack of ascorbic acid (vitamin C), not thiamine. Tuberculosis – ATS is incorrect and outdated; effective TB treatment uses specific anti-tubercular drugs, and BCG, not ATS, is the related vaccine. Tetanus – BCG is wrong because BCG is for tuberculosis; tetanus prevention uses tetanus toxoid and tetanus immunoglobulin. Rickets – ascorbic acid is wrong because rickets results from vitamin D deficiency, often linked with lack of sunlight or poor diet, not vitamin C deficiency.

Common Pitfalls:
A common pitfall is to confuse BCG with other vaccines or mistakenly match any vitamin with any deficiency disease without careful recall. Another is to be misled by partially familiar abbreviations such as ATS. To avoid errors, practice a small set of high yield disease–agent pairs: scurvy–vitamin C, rickets–vitamin D, beriberi–thiamine, pellagra–niacin, tuberculosis–BCG and malaria–chloroquine or other antimalarials. Having these firmly memorised makes it much easier to quickly spot the correctly matched pair in exam questions.

Final Answer:
The correctly matched pair from the list is Malaria – Chloroquine.