Classification — nutrient deficiency diseases: choose the pair that is NOT a correct “nutrient : deficiency disease” match.

Introduction / Context:
Three pairs correctly link a nutrient to a classic deficiency disease. One pair mismatches the disease to the nutrient.

Given Data / Assumptions (spelling normalized):

• Proteins : Marasmus (or kwashiorkor) → protein-energy malnutrition.
• Iodine : Goitre → thyroid enlargement due to iodine deficiency.
• Iron : Anaemia → iron-deficiency anaemia.
• Sodium : Rickets → incorrect; rickets is due to vitamin D deficiency (plus calcium/phosphate issues), not sodium.

Concept / Approach:
Check standard medical associations; select the sole mismatch.

Step-by-Step Solution:

Verification / Alternative check:
Recall: barometer of correctness—iodine↔goitre, iron↔anaemia, protein↔marasmus/kwashiorkor; vitamin D↔rickets.

Why Other Options Are Wrong:
They are correct deficiency links.

Common Pitfalls:
Confusing electrolyte (sodium) disorders with vitamin deficiencies.

Final Answer:
Sodium : Rickets