MRCP UK EXAMINATIONS

You are taking weekend telephone calls for your practice when the father of a 12-year-old boy calls to let you know he is driving his son to the local hospital. The boy was working in the family garage when he drank an unknown substance out of a plastic bottle that he mistakenly thought contained water. Since swallowing some of the substance, the boy has complained of severe throat pain, burning pain in his chest, difficulty swallowing, and nausea. The father tells you that his son is drooling and that he can see a few white “sores” on his tongue and the roof of his mouth.Of the following, the MOST likely substance to cause the boy’s symptoms and physical findings is: