<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 33-year-old female presents with recent onset of painful urination, fever, and right flank pain. Urinary sediment analysis is positive for the presence of white blood cell casts and Gram-negative bacteria. She has not recently started any new medications. What is the most likely diagnosis in this patient?? A: Pelvic Inflammatory Disease, B: Acute Interstitial Nephritis, C: Pyelonephritis, D: Cystitis, E: Appendicitis,  <response>: This is a patient with symptoms of dysuria painful urination, fever, and flank pain in the setting of pyuria white blood cells in the urine and bacteriuria bacteria in the urine. The presence of white blood cell casts indicates inflammation in the kidney itself. The most likely diagnosis given these findings is pyelonephritis, which is a bacterial infection of the kidney. Pelvic inflammatory disease would not explain the urinary findings. Acute interstitial nephritis may cause white cell casts but would not cause bacteriuria. Cystitis is a bladder infection and would not cause flank pain or casts. Appendicitis would not explain the urinary findings.C: Pyelonephritis 