29. Which sequence of blood flow can be observed in either a reptile or a mammal? (A) left ventricle → aorta → lungs → systemic circulation. (B) right ventricle → pulmonary vein → pulmocutaneous circulation. (C) pulmonary vein → ventricle → left atrium → pulmonary circuit(D)pulmonary vein → left atrium → ventricle → pulmonary circuit