Final answer:
The cause of death in this patient is Sudden sniffing syndrome.
Step-by-step explanation:
The cause of death in this patient is E. Sudden sniffing syndrome. Sudden sniffing syndrome refers to a condition that can occur with the misuse of volatile substances, such as chloroform. It can lead to serious health complications, including cardiac arrest and respiratory failure. The symptoms described in the question, such as unconsciousness, dilated pupils, absent reflexes, and pulselessness, are consistent with the effects of sniffing volatile substances.