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: ENT
Not true about Frontal sinus 
Select and explain. 
A. Osteomas are common, B. Sinusitis leads to morning headaches, C. Opens into middle meatus, D. Present at Birth
D: Present at Birth
Answer: D: Present at Birth 
Explanation: None