This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Which of the following is true about rheumatic fever 
Select and explain. 
A. Characteristic manifestation of carditis in previously unaffected individuals is mitral stenosis, B. Chorea occurs in the absence of other manifestations after prolonged latent period, C. Isolated aoic valve involvement is most common, D. 90% of the patients with acute rheumatic fever proceed to rheumatic ea disease
B: Chorea occurs in the absence of other manifestations after prolonged latent period
Answer: B: Chorea occurs in the absence of other manifestations after prolonged latent period 
Explanation: Answer- B. Chorea occurs in the absence of other manifestations after prolonged latent periodAcute rheumatic fever (ARF) is a multisystem disease resulting from an autoimmune reaction to infection with group A streptococcus.The endocardium, pericardium, or myocardium may be affected. Valvular damage is the hallmark of rheumatic carditisThe mitral valve is almost always affected, sometimes together with the aoic valve; isolated aoic valve involvement is rare.Early valvular damage leads to regurgitation.usually as a result of recurrent episodes, leaflet thickening, scarring, calcification, and valvular stenosis may develop.Therefore the characteristic manifestation of carditis in previously unaffected individuals is mitral regurgitation, sometimes accompanied by aoic regurgitation.