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
Palpable Retrosternal goiter is: 
Select and explain. 
A. Substernal., B. Plunging., C. Nodular., D. Intra-thoracic.
A: Substernal.
Answer: A: Substernal. 
Explanation: None