Rheumatic fever (RF) is an inflammatory disease following infection from Streptococcus bacteria. It mainly affects children between ages 5 and 15 and occurs approximately 20 days after strep throat or scarlet fever. Severe RF ca in degeneration of the heart valves. Based on this scenario, RF is most likely to cause
A) uncoordinated contraction of ventricles.
B) "backslide" of blood from a ventricle to an atrium.
C) faster heartbeat.
D) slower heartbeat.