</span>Cephalization<span> is considered an evolutionary trend, whereby nervous tissue, over many generations, becomes concentrated toward one end of an organism. This process eventually produces a head region with sensory organs</span>
The correct answer among the choices listed above is the second option. Flatworms have a concentration of nerve tissue and organs in one end of the body. This characteristic is referred as cephalization. It is a tendency in the development of organisms to localization of important parts in one part.
Ependymal cell present in the central nervous system has an important role in production and control of cerebrospinal fluid (CSF). This ciliated cell acts as sensory for coordination to cellular signaling in the production and control of CSF.
