Final answer:
Carbon dioxide is more soluble in blood than oxygen and it is carried in four forms in the blood: dissolved in plasma, as carbaminohemoglobin, bound to plasma proteins, and as bicarbonate ions.
Step-by-step explanation:
The correct statement regarding these gases is that carbon dioxide is carried in four forms in the blood. Carbon dioxide is more soluble in blood than oxygen and is transported by dissolution directly into the blood, binding to hemoglobin (forming carbaminohemoglobin), binding to plasma proteins, or carrying as a bicarbonate ion (HCO3-). Despite carbon dioxide's high affinity for hemoglobin, oxygen also binds to hemoglobin, and it has a greater affinity compared to carbon monoxide.