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
Earliest tumour to appear after bih is? 
Select and explain. 
A. Sternomastoid tumour, B. Cystic hygroma, C. Branchial cyst, D. Lymphoma
B: Cystic hygroma
Answer: B: Cystic hygroma 
Explanation: Ans. is 'b' i.e., Cystic hygroma