<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 33-year-old man presents to his primary care physician for left-sided knee pain. The patient has a history of osteoarthritis but states that he has been unable to control his pain with escalating doses of ibuprofen and naproxen. His past medical history includes diabetes mellitus and hypertension. His temperature is 102.0F 38.9C, blood pressure is 167108 mmHg, pulse is 100min, respirations are 14min, and oxygen saturation is 98 on room air. Physical exam reveals a warm and tender joint that is very tender to the touch and with passive range of motion. The patient declines a gait examination secondary to pain. Which of the following is the best next step in management?? A: Antibiotics, B: Arthrocentesis, C: Colchicine, D: IV steroids, E: Rest, elevation, and ice,  <response>: This is a clinical vignette describing a patient with acute worsening of chronic left knee pain and signs of systemic inflammation including fever, hypertension, and tachycardia. The key findings are an acutely swollen, warm, and tender knee joint concerning for septic arthritis given the fever and systemic signs. The best next step would be to perform an arthrocentesis to analyze the synovial fluid and confirm the diagnosis. Antibiotics would be premature without confirming infection. Colchicine is used for gout rather than septic arthritis. IV steroids could worsen an infection. Rest, ice, and elevation alone would be insufficient to diagnose and treat suspected septic arthritis.B: Arthrocentesis 