Final answer:
Option 3). Anaphylactic shock is a severe allergic reaction that can be life-threatening. Signs include decreased blood pressure, heavy breathing, itching or burning, edema, and difficulty breathing.
Step-by-step explanation:
An allergen can cause anaphylactic shock, a severe and sometimes fatal allergic reaction. Anaphylactic shock manifests as low blood pressure, dyspnea (difficulty breathing), edema (swelling), burning or itchy sensations, and heavy breathing. It's crucial to remember that, if left untreated, anaphylactic shock can be lethal. Epinephrine is frequently used to counteract the effects of anaphylaxis and can be lifesaving. It is usually supplied by an autoinjector like an EpiPen®. Hence, Option 3) is the correct answer.