Final answer:
The volatile anesthetics affect cerebral blood flow to differing degrees, with desflurane having the greatest impact followed by sevoflurane and isoflurane.
Step-by-step explanation:
Among the most commonly used volatile anesthetics today, the effects of desflurane, isoflurane, and sevoflurane on cerebral blood flow (CBF) vary. Each anesthetic increases CBF to a different extent when used during surgery. While desflurane is known to cause the most significant increase in CBF due to its low blood solubility and rapid effect on the vasculature, sevoflurane is considered to have a lesser effect, and isoflurane even less so. Thus, the effects of these volatile anesthetics on cerebral blood flow from greatest to least would be represented by option a. Desflurane > Sevoflurane > Isoflurane.