Question

the cerebellar hemispheres are separated by a band of cortex called the
flocculonodular lobe.
vermis.
folia.
arbor vitae.
pyramid.

Explanation:

The cerebellum has two hemispheres. The vermis is a midline structure (a band of cortex) that separates the two cerebellar hemispheres. The flocculonodular lobe is part of the vestibulocerebellum. Folia are the small leaf - like structures of the cerebellar cortex. Arbor vitae is the white matter of the cerebellum that has a tree - like appearance. The pyramid is a part of the medulla oblongata (not directly related to separating cerebellar hemispheres).

Answer:

vermis.