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
Chignon is: 
Select and explain. 
A. Cephal hematoma, B. Artificial caput, C. Scalp laceration, D. Excessive moulding
B: Artificial caput
Answer: B: Artificial caput 
Explanation: A vacuum is applied (usually 0.2 kg/cm2 for vacuum extraction of a baby).
The scalp is sucked into the cup and an artificial caput is produced. This chignon usually disappears in a few hours.