Xiaoming needs oral penicillin V potassium tablets because of a cold and tonsillitis. After taking it, the first penicillin component in the four chambers of the heart is () A.

The heart has four chambers, left and right ventricles and left and right atria, and the blood vessels connected with the four chambers are shown as follows:

Pathways in blood circulation: pulmonary circulation: right ventricle-pulmonary artery-pulmonary capillary network-pulmonary vein-left atrium,

Systemic circulation: left ventricle-aorta-capillary network all over the body-superior and inferior vena cava-right atrium,

So this person needs oral penicillin because of tonsillitis. The drug is absorbed into the capillaries of the digestive tract, collected into the superior and inferior vena cava, enters the right atrium, then flows into the right ventricle, starts pulmonary circulation, then flows into the left atrium and left ventricle, and reaches the focus with systemic circulation. So penicillin first appeared in the right atrium in the four chambers of the heart.

So choose: D.