Question

why is an untreated acute allergic reaction a life - threatening situation?
vomiting and diarrhea may cause dehydration
airway constriction may lead to low blood pressure and shock
peripheral vasoconstriction elevates blood pressure
none of the above

Explanation:

An untreated acute allergic reaction can be life - threatening because vomiting and diarrhea can cause severe dehydration, and airway constriction can lead to low blood pressure and shock. Peripheral vasoconstriction is not a typical life - threatening consequence in the context of acute allergic reactions in the way described here.

Answer:

Vomiting and diarrhea may cause dehydration, Airway constriction may lead to low blood pressure and shock