<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 45-year-old woman comes to the emergency department complaining of abdominal pain for the past day. The pain is situated in the right upper quadrant, colicky, 810, and radiates to the tip of the right shoulder with no aggravating or relieving factors. The pain is associated with nausea but no vomiting. She tried to take over-the-counter antacids which relieved her pain to a certain extent, but not entirely. She does not smoke cigarettes or drink alcohol. She has no past medical illness. Her father died of pancreatic cancer at the age of 75, and her mother has diabetes controlled with medications. Temperature is 38C 100.4F, blood pressure is 12589 mm Hg, pulse is 104min, respiratory rate is 20min, and BMI is 29 kgm2. On abdominal examination, her abdomen is tender to shallow and deep palpation of the right upper quadrant.Laboratory testComplete blood countHemoglobin 13 gdLWBC 15,500mm3Platelets 145,000mm3Basic metabolic panelSerum Na 137 mEqLSerum K 3.6 mEqLSerum Cl- 95 mEqLSerum HCO3- 25 mEqLBUN 10 mgdLSerum creatinine 0.8 mgdLLiver function testTotal bilirubin 1.3 mgdLAST 52 ULALT 60 ULUltrasonography of the abdomen shows normal findings. What is the best next step in management of this patient?? A: Emergency cholecystectomy, B: Percutaneous cholecystostomy, C: Cholescintigraphy, D: CT scan, E: Reassurance and close follow up,  <response>: This is a clinical case scenario describing a 45-year-old woman presenting with right upper quadrant abdominal pain, nausea, and fever. The description of the pain being colicky and radiating to the right shoulder tip suggests biliary etiology. Lab tests show elevated WBC count indicating infectioninflammation and mildly elevated liver enzymes. Ultrasound is normal. The clinical presentation is most consistent with acute cholecystitis. However, the ultrasound being normal makes the diagnosis uncertain. Additional imaging is needed to confirm the diagnosis before proceeding to treatment. Of the options given, cholescintigraphy hepatobiliary iminodiacetic acid scan would be most useful to evaluate cystic duct patency and gallbladder function. This would help confirm acute cholecystitis and guide further management. CT scan may miss early acute cholecystitis and is not necessary at this stage. Emergent cholecystectomy or cholecystostomy would be premature without confirming the diagnosis. Reassurance and follow up alone would be inappropriate in a potentially serious condition.C: Cholescintigraphy 