Concept:
Iron is an essential mineral required for the formation of haemoglobin in red blood cells.
Deficiency of iron leads to:
• Reduced haemoglobin level
• Decreased oxygen-carrying capacity of blood
• Anaemia
This condition is commonly known as Iron Deficiency Anaemia or Nutritional Anaemia.
Step 1: Analyze option A.
Rickets is caused by deficiency of Vitamin D and affects bones.
Hence, option A is incorrect.
Step 2: Analyze option B.
Pellagra occurs due to deficiency of niacin (Vitamin \(B_3\)).
Hence, option B is incorrect.
Step 3: Analyze option C.
Nutritional Anaemia is commonly associated with iron deficiency and lowered haemoglobin level.
Hence, option C is correct.
Step 4: Analyze option D.
Scurvy is caused by deficiency of Vitamin C.
Hence, option D is incorrect.
Therefore, the correct answer is:
\[
\boxed{(C)\ \text{Nutritional Anaemia}}
\]