Final answer:
In hyperkalemic emergencies, the first-line therapy is typically calcium gluconate to stabilize the heart, although additional treatments may include insulin with dextrose and diuretics like furosemide.
Step-by-step explanation:
The first-line therapy for hyperkalemic emergencies depends on the severity of the condition and the specific clinical scenario. However, in general, the initial treatment of severe or symptomatic hyperkalemia includes stabilizing the heart to prevent arrhythmias. Therefore, the correct answer to the student's question is number 3: administering calcium gluconate. This medication helps to stabilize the cardiac membrane. The management of emergency hyperkalemia might also involve regular insulin with dextrose, to help shift potassium back into cells, and diuretics like furosemide to promote potassium excretion, but these are not typically first-line Immediate treatments.