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: Surgery
Which is never a cause of thyroglossal fistula - 
Select and explain. 
A. Infection of thyroglossal cyst, B. Inadequate removal of thyroglossal cyst, C. Congenital, D. None of the above
C: Congenital
Answer: C: Congenital 
Explanation: • A thyroglossal fistula usually presents as discharging sinus in the midline of the neck in the line of thyroid descent.
• It is never congenital but follows infection or inadequate removal of a thyroglossal cyst
• Acquired condition
Clinical Features
• Presentation is with a fistulous opening near to the midline of the neck
• The fistula may become infected and discharge pus
Treatment
• The fistula should be excised along with the thyroglossal tract upto the base of the tongue.
• This requires removing the central (middle one third) of the hyoid bone.