What is the correct sequence in which a drop of blood returning from the body encounters the heart valves?

A) right atrioventricular valve → aortic semilunar valve → left atrioventricular valve → pulmonary semilunar valve
B) right atrioventricular valve → pulmonary semilunar valve → left atrioventricular valve → aortic semilunar valve
C) left atrioventricular valve → pulmonary semilunar valve → right atrioventricular valve → aortic semilunar valve
D) pulmonary semilunar valve → left atrioventricular valve → aortic semilunar valve → right atrioventricular valve
E) left atrioventricular valve → aortic semilunar valve → right atrioventricular valve → pulmonary semilunar valve

Blood returning from the body enters the right atrium and passes through the right atrioventricular valve (tricuspid valve) into the right ventricle. From there, it passes through the pulmonary semilunar valve into the pulmonary artery, which carries it to the lungs to exchange carbon dioxide for oxygen. Oxygen-rich blood returns to the heart via the pulmonary vein, enters the left atrium, and passes through the left atrioventricular valve (mitral valve) into the left ventricle. Finally, it passes through the aortic semilunar valve into the aorta to be distributed to the rest of the body. Therefore, the correct sequence is: right atrioventricular valve → pulmonary semilunar valve → left atrioventricular valve → aortic semilunar valve.