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
A one-month-old female child has swelled over the back in the sacral region. There is no cough impulse in the swelling. X-ray examination shows erosion of the coccyx. The most likely clinical diagnosis would be - 
Select and explain. 
A. Meningocele, B. Lipoma, C. Sacro-coccygeal teratoma, D. Neurofibroma
C: Sacro-coccygeal teratoma
Answer: C: Sacro-coccygeal teratoma 
Explanation: In meningocele, there will be cough impulse.