Which of the Following Statements Is TRUE Regarding CO₂ in the Mammalian

Which of the following statements is TRUE regarding CO₂ in the mammalian bloodstream?

A) Like oxygen, CO₂ is transported through the mammalian bloodstream via hemoglobin; however, CO₂ binds to hemoglobin at $\beta$ subunits rather than heme groups.
B) Unlike oxygen, CO₂ is transported through the mammalian bloodstream by myoglobin.
C) All CO₂ is transported through the mammalian bloodstream as a dissolved gas, and is carried directly in the plasma.
D) CO₂ is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid.
E) In the mammalian bloodstream, CO₂ is much less soluble than O₂.