17 A 22-year-old man is brought to the hospital emergency department by a friend, who found him unconscious in hisapartment after trying to contact him for 3 days. On arrival, the patient is in a state of respiratory depression. He experiences convulsions for several minutes, followed by cardiac arrest. Advanced cardiac life support measures are instituted, and he is stabilized and intubated. On physical examination, there are needle tracks in the left antecubital fossa, and a loud diastolic heart murmur is audible. The patient has a temperature of 39.2C. Use of which of the following substances most likely produced these findings? (A) Cocaine (B) Ethanol (C) Flurazepam (D) Heroin (E) Meperidine (F) Phencyclidine (G) Phenobarbital