Answer:
The correct answer is 1. Allergy to sulfa drugs.
Step-by-step explanation:
Furosemide is a loop diuretic and it is given in patients with hypertension and in treatment of edemas.
If a patient is allergic to sulfa or sulfonamides, then the patient may also be allergic to furosemide. So the doctor must ask the patient if he is allergic to any drug.