The correct option is A Roof of paracoel
The posterior portion of cerebral hemispheres touches the optic lobes so that the diencephalon is not distinct from the dorsal side. The cavities of cerebral hemispheres are known as paracoel or lateral ventricles, which are anteriorly connected with rhinocoel. The floor and lateral walls of paracoel are thick called corpora striata, the roof of paracoel is called pallium.
So, the correct answer is option A.