A 15 Year Old Girl Developed Fever,aching Joints,and a Heart

A 15 year old girl developed fever,aching joints,and a heart murmur.Her past medical history was negative,except for a "Strep throat" approximately 6 weeks prior,for which she did not seek treatment.An endomyocardial biopsy was performed,via the external jugular vein,a representative section of which is shown in the accompanying photomicrograph.Which one of the following best describes the pathology seen in the biopsy?

A) Acute inflammation
B) Aschoff nodule
C) Chronic inflammation
D) Rheumatoid nodule
E) Rheumatic fever