This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pediatrics
In morbus caeruleus foramen ovole closes after 
Select and explain. 
A. 6 months, B. 2 years, C. 1 year, D. Never
D: Never
Answer: D: Never 
Explanation: In few cases, foramen ovale remains patent throughout life and gives rise to cyanosis, a condition called as Morbus caeruleus.(Refer: Nelson's Textbook of Pediatrics, SAE, 1st edition, pg no. 2162)