Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: In patients with digitalized congestive heart failure, when administering a diuretic, it must necessarily be:
Options: <1> A loop diuretic or high ceiling. <2> A thiazide. <3> An osmotic diuretic. <4> A potassium-sparing diuretic. <5> A diuretic carbonic anhydrase inhibitor.
Output:
4