What would be expected to happen?

The pH scale is used to rank solutions in terms of acidity or basicity (alkalinity). In blood the ph is near to neutral. Human blood needs to keep its pH near 7.4, and avoid shifting significantly higher or lower – even if acidic or basic substances enter or leave the bloodstream.

Buffers are vital for maintaining stability. One of the buffers that contributes to the pH scale stability in human blood is carbonic acid which is formed when carbon dioxide enters the bloodstream and combines with water. Reaching the lungs it's converted back into water and released as a waste product. "A decrease in the concentration of H2CO3 and an increase in the concentration of H2O" is the correct answer.