Which of the following procedures is used when kidneys can no longer filter waste?

Hemodialysis is the correct choice because it is a medical procedure specifically designed to compensate for the loss of kidney function. When kidneys fail or can no longer effectively filter waste products from the blood, hemodialysis is employed to perform this essential function artificially. During the procedure, blood is drawn from the body, filtered through a dialysis machine that removes waste, excess fluid, and electrolytes, and then returned to the body. This process helps maintain the body's chemical balance and removes harmful substances, making it critical for individuals with renal failure.

In contrast, urinalysis is a diagnostic test that evaluates urine for various substances and indicators but does not treat kidney failure. Urinary catheterization involves inserting a tube into the bladder to drain urine but does not address the underlying issue of kidney function. A renal transplant is a surgical procedure to replace a diseased kidney with a healthy one, which is a long-term solution, but it is not a procedure used when immediate filtration is required.