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
Internal jugular vein is a continuation of: 
Select and explain. 
A. Common Facial Vein, B. External Jugular Vein, C. Sigmoid Sinus, D. Superior Petrosal Sinus
C: Sigmoid Sinus
Answer: C: Sigmoid Sinus 
Explanation: None