What is the primary function of the urinary system?

The primary function of the urinary system is indeed to filter blood and create urine. This complex system plays a vital role in maintaining homeostasis by regulating the composition and volume of blood. It achieves this by filtering out waste products, excess substances, and toxins from the bloodstream, which are then excreted from the body as urine.

The process begins in the kidneys, where blood is filtered through specialized structures called nephrons. The kidneys remove waste compounds such as urea, creatinine, and various ions while retaining necessary substances and fluids. The resulting urine is then transported to the bladder, where it is stored until it is excreted.

The other options do touch upon functions of different systems in the body but do not accurately describe the primary function of the urinary system. For instance, regulating body temperature is primarily handled by the integumentary system, while transporting nutrients is a function of the circulatory system. The production of hormones is chiefly the role of the endocrine system. Thus, the emphasis on filtering blood and generating urine distinctly highlights the urinary system's crucial role in waste management and fluid balance.