Final answer:
The correct sequence of heart valves through which blood flows from the vena cava through the heart is tricuspid, pulmonary semilunar, bicuspid, and aortic semilunar.
Step-by-step explanation:
The question refers to the types of valves in the human heart and the order through which blood flows. There are four main valves in the heart: the tricuspid valve, the pulmonary semilunar valve, the bicuspid or mitral valve, and the aortic semilunar valve. The correct order of blood flow from the vena cava through the heart is tricuspid valve, pulmonary semilunar valve, bicuspid valve, and aortic semilunar valve.
Therefore, the correct option for the valves in the order through which blood flows from the vena cava through the heart is:
a. tricuspid, pulmonary semilunar, bicuspid, aortic semilunar