This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
Is 70 year old man was administered penicillin intravenous within five minutes, he developed generalized uicaria, swelling of lips, hypotension and bronchospasm. the first choice is to administer 
Select and explain. 
A. Chlorpheneramine inj, B. Epinephrine inj, C. High dose hydrocoisone tablet, D. Nebulized salbutamol
B: Epinephrine inj
Answer: B: Epinephrine inj 
Explanation: Epinephrine (adrenaline) is a drug of choice for anaphylactic shock. it is given by subcutaneous or intramuscular route in a concentration of 1:1000. intravenous route is rarely used but at match but that much lower concentration(1:10,000) Refer kDT 6/e p128