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: Unknown
Following tumour produce a marked elevation of: 
Select and explain. 
A. Alpha feto protein, B. Placental alkaline phosphatase, C. Human placental lactogen, D. CA 125
A: Alpha feto protein
Answer: A: Alpha feto protein 
Explanation: • Yolk sac tumors are those that resemble the yolk sac, allantois, and extraembryonic, mesenchyme.
• They are also known as endodermal sinus tumors.
• Yolk sac tumors can be seen in males and females, involving the testis, ovary, and other sites, such as the
mediastinum.
• Pure yolk sac tumor is the most common testicular neoplasm in prepubertal children.
• Almost all the patients with a yolk sac tumor either in pare form or mixed form have a significantly elevated serum
Alpha fetoprotein (AFP).