Cerebrospinal fluid is produced by

The correct option is A Choroid plexus

Plexus is the branching network of blood vessels or veins. Cerebrospinal fluid is produced by choroid plexus. It is a multi-lobed vascular structure of the pia mater that projects into the ventricles of the brain. The modified ependymal cells of the vascular membrane produce 500 ml of cerebrospinal fluid per day. Cerebrospinal fluid is a clear watery fluid which fills the space between the arachnoid membrane and the pia mater. The cerebrospinal fluid (CSF) is produced from arterial blood by the choroid plexuses of the lateral and fourth ventricles by a combined process of diffusion, pinocytosis and active transfer. So, the correct answer is option B.