This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Embryology, Subject name: Anatomy
Sacrococcygeal teratoma is due to: 
Select and explain. 
A. Primitive streak, B. Notochord, C. Closure of caudal neuropore, D. Cloacal membrane
A: Primitive streak
Answer: A: Primitive streak 
Explanation: Ans. a. Primitive streakSACROCOCCYGEAL TERATOMA (ST)It is the most common germ cell tumor of childhood.Sacrococcygeal teratoma (ST) is a tumor that arises from remnants of the primitive streak, which normally degenerates and disappears.Sacrococcygeal teratomaIt is derived from pluripotent cells of the primitive streak and often contains various types of tissue (e.g., bone, nerve, hair).It occurs more commonly in female infants and usually becomes malignant during infancy (must be surgically removed by age 6 months).