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: Anatomy
Which among the following statement is not true? 
Select and explain. 
A. Superior thyroid aery is a branch of ext. carotid a, B. Posterior branch of superior thyroid aery supplies parathyroid gland, C. Inferior thyroid aery is branch of thyrocervical trunk, D. Thyroid ima aery is invariably a branch of arch of aoa
D: Thyroid ima aery is invariably a branch of arch of aoa
Answer: D: Thyroid ima aery is invariably a branch of arch of aoa 
Explanation: The thyroid ima aery is infrequent (10%) and variable in its orgin. It arises from the brachiocephalic aery, aoic arch, right common carotid aery, internal thoracic aery, or subclan aery.