1. A 66-year-old m an com plained to his physician that he had urinated very little over the past 24 hours. The m an was being treated w ith digoxin, furosem ide, and captopril for congestive heart...

1. A 66-year-old m an com plained to his physician that he had urinated very little over the past 24 hours. The m an was being treated w ith digoxin, furosem ide, and captopril for congestive heart failure, and the therapy had im proved his cardiac conditions. Two days ago, the patient had pain on m ovem ent of his left leg that got better w ith two ibuprofen tablets. The physician found no clinical signs of intravascular volum e depletion and increased the dose of furosem ide, but 6 hours later, urination was not im proved. Which of the follow ing actions m ost likely m ediated the patient’s oliguria? A. Ibuprofen-m ediated decrease of the glom erular ltration rate B. Worsening of cardiac failure despite the therapy C. Furosem ide-m ediated decrease of renin secretion D. Digoxin-m ediated decrease of the glom erular ltration rate E. Furosem ide-induced hypokalem ia