This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
Superior vena cava is formed by? 
Select and explain. 
A. Vitelline veins, B. Supracardinal vein, C. Infracardinal vein, D. Common cardinal vein
D: Common cardinal vein
Answer: D: Common cardinal vein 
Explanation: Developmentally, the superior vena cava consists of two pas: first and second. The first pa develops from the right anterior cardinal vein caudal to oblique transverse anastomosis. The second pa develops from the right common cardinal vein. Reference: Textbook of clinical embryology, Vishram Singh,1st edition, page no.223-224