<prompt> Third ventricle is derived from -MesencephalonRhombencephalonThalamecephalonTelencephalon  <response>: Ans. is c i.e., Thalamecephalon Part of brainSubdivisionsCavityo Forebrain Prosencephalono Telencephalon cerebrumCerebral hemisphereo Diencephalon thalamencephalon Thalamus, hypothalamus, metathalamus including medial and lateral genialate bodies, epithalamus, sunthalamus.Lateral ventricle Third ventricleo Midbrain Mesencephalono Crus cerebri, substantia nigra, tegmentum and tectumCerebral aqueducto Hindbrain rhombencephalono Metencephalon pons, cerebellumo Mylencephalon medullaFourth ventricle 