Which of the following organs is responsible for filtering blood and producing urine?

• A. Liver
• B. Kidney
• C. Pancreas
• D. Lungs

Answer: (B)

The kidney is the organ responsible for filtering blood and producing urine. It plays a critical role in the body's renal system, which is vital for maintaining homeostasis. The kidneys filter out toxins, waste products, and excess substances from the blood, which are then excreted in the form of urine.

This organ regulates various bodily functions, including electrolyte balance, fluid balance, and blood pressure, and is crucial for removing waste products resulting from metabolism. As blood flows through the kidneys, nephrons—functional units of the kidney—filter out unwanted materials while retaining necessary substances. The processed waste is then concentrated into urine, which is stored in the bladder until excretion.

The liver primarily functions in metabolism, detoxification, and producing bile for digestion. The pancreas plays essential roles in both the digestive and endocrine systems, primarily by producing digestive enzymes and hormones like insulin. The lungs are focused on gas exchange, bringing oxygen into the body and removing carbon dioxide. Thus, the kidneys are specifically tasked with the function identified in the question.