Step 1: Structure of Heart:
The human heart has four chambers:
Right atrium
Right ventricle
Left atrium
Left ventricle
Step 2: Flow of Blood:
Blood flows from left atrium → left ventricle.
Blood flows from right atrium → right ventricle.
Blood never flows directly from right atrium to left ventricle.
Step 3: Conclusion:
Therefore, correct blood flow includes both options (A) and (B).
Step 4: Final Answer:
Blood flows from left atrium to left ventricle and from right atrium to right ventricle.