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: Anaesthesia
Use of nitrous oxide is contraindicated in all of the following surgeries, EXCEPT: 
Select and explain. 
A. Tympanic membrane grafting, B. Pneumoencephalography, C. Vitreoretinal surgery, D. Exenteration operation
D: Exenteration operation
Answer: D: Exenteration operation 
Explanation: Conditions in which nitrous oxide might be hazardous include, Air embolism Pneumothorax Acute intestinal obstruction Intracranial air (tension pneumocephalus following dural closure or pneumoencephalography) Pulmonary air cysts Intraocular air bubbles Tympanic membrane grafting Ref: Morgan, Jr. G.E., Mikhail M.S., Murray M.J. (2006). Chapter 7. Inhalation Anesthetics. In G.E. Morgan, Jr., M.S. Mikhail, M.J. Murray (Eds), Clinical Anesthesiology, 4e.