This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pediatrics
Preventable causes of Mental Retardation are 
Select and explain. 
A. Downs, B. Phenylketonuria, C. Cretinism, D. Cerebral palsy
C: Cretinism
Answer: C: Cretinism 
Explanation: Cretinism is congenital iron deficiency syndrome which can be preventable by intake in required amounts. Reference: GHAI Essential pediatrics, 8th edition