<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A previously healthy 4-year-old boy is brought to the emergency department because of a 1-day history of pain and swelling of his left knee joint. He has not had any trauma to the knee. His family history is unremarkable except for a bleeding disorder in his maternal uncle. His temperature is 36.9C 98.4F. The left knee is erythematous, swollen, and tender; range of motion is limited. No other joints are affected. An x-ray of the knee shows an effusion but no structural abnormalities of the joint. Arthrocentesis is conducted. The synovial fluid is bloody. Further evaluation of this patient is most likely to show which of the following findings?? A: Elevated antinuclear antibody levels, B: Decreased platelet count, C: Prolonged prothrombin time, D: Prolonged partial thromboplastin time, E: Synovial fluid leukocytosis,  <response>: This is a clinical case scenario describing a 4-year-old boy with acute onset of left knee pain, swelling, and limited range of motion. There is no history of trauma and no other joints are affected. X-ray shows knee joint effusion but no bony abnormalities. Arthrocentesis reveals bloody synovial fluid. The acute monoarticular presentation along with bloody synovial fluid raises suspicion for a bleeding disorder as the cause. The family history of a bleeding disorder in the maternal uncle also supports this. The correct answer would provide evidence for a bleeding disorder. Prolonged PT and PTT would indicate impaired coagulation. Decreased platelets could also contribute to abnormal bleeding. The other findings - antinuclear antibodies and synovial leukocytosis - would not be expected in a bleeding disorder.D: Prolonged partial thromboplastin time 