<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-year-old boy is brought to the emergency department because of pain and swelling of his right knee joint for 1 day. He has not had any trauma to the knee. He was born at term and has been healthy since. His maternal uncle has a history of a bleeding disorder. His temperature is 37.1C 98.8F and pulse is 97min. The right 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 done. The synovial fluid is bloody. Further evaluation of this patient is most likely to show which of the following?? A: Synovial fluid leukocytosis, B: Decreased platelet count, C: Prolonged partial thromboplastin time, D: Elevated erythrocyte sedimentation rate, E: Elevated antinuclear antibody levels,  <response>: This is a clinical case scenario about a 3-year-old boy with acute swelling and pain in his right knee joint. The key findings are:- No history of trauma to the knee- Family history of a bleeding disorder in maternal uncle- Physical exam shows right knee is swollen, tender, limited range of motion, and bloody synovial fluid on arthrocentesis. - X-ray shows knee effusion but no structural abnormalities.The bloody synovial fluid along with family history of a bleeding disorder strongly suggests an underlying coagulation abnormality as the cause of the knee swelling and pain. The other findings do not point towards an infectious, inflammatory or autoimmune cause.Of the choices given, a prolonged partial thromboplastin time PTT would be most consistent with an inherited bleeding disorder like hemophilia. PTT assesses the intrinsic coagulation pathway and would be abnormal in hemophilia A or B. The other lab findings - leukocytosis, decreased platelets, elevated ESR, and positive ANA - do not fit with the clinical presentation.C: Prolonged partial thromboplastin time 