What Is the Mechanism of Action of the Osmotic Diuretic

What is the mechanism of action of the osmotic diuretic mannitol in the setting of increased ICP?

A) Mannitol crosses the blood-brain barrier and removes water from the cerebral vascular spaces.
B) Mannitol increases the permeability of the loop of Henle,causing water to leave the nephrons.
C) Mannitol enters the ventricles of the brain,causing fluid to leave the choroid plexus and enter the circulation for delivery to the kidneys.
D) Mannitol remains in the plasma,creating an osmotic gradient that draws water from the brain into the cerebral capillaries.