A patient is admitted with glomerulonephritis. IV gentamicin therapy is started after cultures indicate gram-negative bacilli in the blood. The patient also receives IV furosemide (Lasix). Which organ monitored for signs and symptoms of toxicity?

A. Pancreas: Neither of these drugs is primarily known for pancreatic toxicity. B. Kidneys: Gentamicin (an aminoglycoside) is nephrotoxic. When combined with Furosemide (a loop diuretic), the risk of acute kidney injury is increased. Both drugs are also ototoxic (affecting hearing). C. Liver: These drugs are primarily cleared or exert toxicity through the renal and auditory systems, not the hepatic system. D. Brain: While they can cause dizziness (ototoxicity), the primary organic toxicity of concern for this drug combination is renal failure.