Answer : B Ependymoma
Ependymoma originates in the lining of the cavities that contain cerebrospinal fluid.
The tumor is most common in the fourth ventricle, where it produces obstruction and results in hydrocephalus.
The cells of an ependymoma characteristically have an “epithelial” appearance, similar to that of normal ependymal cells.
They may arrange around blood vessels forming perivascular pseudorosettes.
Ependymomas may also originate from the lining of the central canal of the spinal cord and the filum terminale.
Together with astrocytomas ependymomas are the most common neoplasms of the spinal cord. Because of their central location, they cannot be easily resected