This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology, Subject name: Medicine
Consider the following - 1. Kerosene poisoning 2. Organo-phosphorus poisoning 3. Corrosive poisoning 4. Iron poisoning In which of the above is gastric lavage contraindicated? 
Select and explain. 
A. 1 only, B. 1 and 3 only, C. 2 and 4 only, D. l,2, 3and 4
B: 1 and 3 only
Answer: B: 1 and 3 only 
Explanation: Gastric lavage iscontraindicated in corrosive poisoning(strong acids and alkalis) or if petroleum distillates ( kerosene) have been ingested. Reference: Harrison20th edition pg 789