Final answer:
The R pulmonary surface of the heart is primarily made up by the right atrium, which receives deoxygenated blood from the systemic circuit.
Step-by-step explanation:
The of the heart is R pulmonary surfaces primarily made up by the right atrium . The right atrium receives deoxygenated blood from the systemic circuit through the inferior vena cava and the superior vena cava. Once the blood has been oxygenated in the lungs, it returns to the left atrium via the pulmonary veins, but this does not make up the right pulmonary surface. Therefore, the right atrium is the correct answer which corresponds to the structures that define the R pulmonary surface of the heart.