The answer to your question is hemoglobin
<span>The question says,' the purpose of the mucus found within the respiratory system is to .............. The correct option is B. The mucus found in the respiratory system function by trapping foreign particles that enter into the lungs especially thorugh the nose during breathing, thus mucus aid in protecting the lungs.</span>
Your nose and your mouth are both a portal of entry into your body. If you cover one and not the other it defeats the purpose because Bacteria can still enter the system. They are both part of your respiratory system.
