<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 55-year-old woman presents to a physicians clinic for a diabetes follow-up. She recently lost weight and believes the diabetes is winding down because the urinary frequency has slowed down compared to when her diabetes was at its worst. She had been poorly compliant with medications, but she is now asking if she can decrease her medications as she feels like her diabetes is improving. Due to the decrease in urinary frequency, the physician is interested in interrogating her renal function. Which substance can be used to most accurately assess the glomerular filtration rate GFR in this patient?? A: Creatinine, B: Inulin, C: Urea, D: Glucose, E: Para-aminohippurate PAH,  <response>: This is a medical question asking about the most accurate way to assess glomerular filtration rate GFR in a patient with diabetes. The choices given are different substances that can be used to measure GFR. The key points in the question stem are:- 55 year old woman with diabetes - Interested in assessing her renal function and GFR due to decreased urinary frequencyTo accurately assess GFR, we need a substance that is freely filtered by the glomerulus and not reabsorbed or secreted by the tubules. This gives a true measure of the filtration rate.Creatinine and inulin are the best choices for this as they meet the criteria. Creatinine is endogenous while inulin must be administered exogenously. Inulin is considered the gold standard for measuring GFR as it is freely filtered and not reabsorbed or secreted. However, creatinine can also accurately assess GFR and is simpler to measure.Urea, glucose and PAH are not ideal for assessing GFR in this setting. Urea is reabsorbed and secreted by the tubules, glucose is completely reabsorbed, and PAH is secreted by the tubules. These will not give an accurate measure of the true GFR.B: Inulin 