Which of the following statement(s) is (are) true about human heart ?

(a) Right atrium receives oxygenated blood from lungs through pulmonary artery.

(b) Left atrium transfers oxygenated blood to left ventricle which sends it to various parts of the body.

(c) Right atrium receives deoxygenated blood through vena cava from upper and lower body.

(d) Left atrium transfers oxygenated blood to aorta which sends it to different parts of the body.

Let us evaluate each statement regarding the human heart:

• Statement (a) is incorrect: The right atrium receives deoxygenated blood from the body tissues via the vena cava, not oxygenated blood from the lungs. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
• Statement (b) is correct: Oxygenated blood from the lungs enters the left atrium. When the left atrium contracts, this blood is transferred to the left ventricle, which subsequently pumps it to various parts of the body.
• Statement (c) is correct: Deoxygenated blood from the upper and lower parts of the body is collected by the superior and inferior vena cava and emptied into the right atrium.
• Statement (d) is incorrect: The left atrium transfers oxygenated blood to the left ventricle, not directly to the aorta. The aorta is the main artery that arises from the left ventricle to distribute oxygenated blood to the body.

Since statements (b) and (c) are true, option C is the correct choice.