<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 15-year-old girl presents with four days of malaise, painful joints, nodular swelling over her elbows, low-grade fever, and a rash on her chest and left shoulder. Two weeks ago, she complained of a sore throat that gradually improved but was not worked up. She was seen for a follow-up approximately one week later. At this visit her cardiac exam was notable for a late diastolic murmur heard best at the apex in the left lateral decubitus position with no radiation. Which of the following is the best step in the management of this patient?? A: Penicillin therapy, B: NSAIDS for symptomatic relief, C: Aortic valve replacement, D: Mitral valve repair, E: Reassurance that this is a benign murmur and send home,  <response>: This appears to be a case of acute rheumatic fever based on the description of malaise, painful joints, low-grade fever, rash, and history of a recent sore throat. The late diastolic murmur indicates mitral regurgitation, which can occur with rheumatic fever due to inflammation and damage to the mitral valve. The best initial management is penicillin therapy to treat the underlying streptococcal infection and prevent further valve damage. NSAIDs may provide symptomatic relief but do not treat the underlying cause. Valve surgery is not indicated at this stage. Reassurance and discharge would be inappropriate as this patient requires treatment.A: Penicillin therapy 