This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
[{'content': 'Which of the following is not a sign of the skull base fracture? \nSelect and explain. \nA. Fox sign, B. Halo sign, C. Battle sign, D. Racoon eyes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Skull base fracture can have the following presentation: Battle sign: Ecchymosis at the mastoid process due to extravasation of blood Racoon eye / Black eye: Ecchymoses in the periorbital area Target sign / Halo sign: Cerebrospinal fluid (CSF) rhinorrhea Hemotympanum Damage to Cranial nerves VII or VIII - Fox sign is seen in acute hemorrhagic pancreatitis due to bruising over the inguinal ligament.', 'role': 'assistant'}]