The circulatory system

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A student is reading a passage about how the human heart continuously pumps blood to maintain the supply of oxygen and nutrients to all body cells. While learning this, they come across the term ‘double circulation,’ which describes how blood flows through the heart twice in one complete circulation of the body. Based on your understanding, what does double circulation ensure for humans?

• A That blood flows only once through the heart so that oxygen can be transported directly to tissues without mixing with deoxygenated blood
• B That oxygenated and deoxygenated blood mix inside the ventricles which helps regulate body temperature more efficiently
• C That oxygenated blood is kept completely separate from deoxygenated blood, allowing a higher pressure to be maintained for efficient delivery to body organs
• D That the right side of the heart pumps only nutrient-rich blood while the left side pumps only carbon dioxide-rich blood throughout the body

*The correct answer is not shown in the preview.