This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All are causes of sideroblastic anaemia, except 
Select and explain. 
A. Collagen vascular disease, B. Iron deficit, C. Lead poisoning, D. Cutaneous porphyria
B: Iron deficit
Answer: B: Iron deficit 
Explanation: None