Which statement about acute renal failure (ARF) is true?

Acute renal failure (ARF), also known as acute kidney injury (AKI), is characterized by a rapid decline in kidney function, which can indeed last for a period of weeks or, in certain circumstances, up to a year. This condition can arise from various causes such as reduced blood flow to the kidneys, damage to the kidney tissue, or obstruction of the urinary tract. The duration of ARF can vary widely amongst patients, but it is recognized that some individuals may take months to fully recover kidney function, depending on the underlying cause and severity of the injury. This highlights the importance of timely diagnosis and management to alleviate potential long-term consequences of kidney damage.

In contrast to the other statements: ARF is not limited to a few days; while some cases may resolve quickly, many require an extended period for complete recovery. The assertion that ARF does not affect kidney function is inaccurate, as ARF inherently involves a decline in renal function. Furthermore, while dehydration can contribute to kidney injury, it is not the sole cause of ARF and does not mean that ARF is exclusively caused by chronic dehydration. Thus, statement B best reflects the potential timeline and nature of acute renal failure.