Which of the following is not true of respiratory alkalosis?

A)It exists when the blood pH is >7.45.
B)It can result from an increase in the CO₂ level in the blood.
C)It can result in death, if the blood pH reaches 8.0 or above.
D)It causes vasoconstriction of the cerebral blood vessels, which decreases oxygen delivery to the brain.
E)All of these are true of respiratory alkalosis.