This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
Cullen's sign: 
Select and explain. 
A. Bluish discolouration of the flanks, B. Bluish discolouration in the umbilicus, C. Migratory thrombophelebitis, D. Subcutaneous fat necrosis
B: Bluish discolouration in the umbilicus
Answer: B: Bluish discolouration in the umbilicus 
Explanation: (Bluish discolouration in the umbilicus) (1124-Baily & love 24th) (1140-Baily & Love 25th)Acute Pancratitis* Bluish discolouration of the flanks - Grey Turner Sign* Bluish discolouration of the umbilicus - Cullen's sign.