Ans. a. Amnestic syndromeIn amnestic syndrome, degenerative changes in the brain are seen, which is not a pa of normal ageing. `Amnestic SyndromeThe amnestic disorders are characterized by problems with memory function.Some people experience difficulty recalling events that happened or facts that they learned before the onset of the amnestic disorder. This type of amnesia is called retrograde amnesia.Other people experience the inability to learn new facts or retain new memories, which is called anterograde amnesia.People with amnestic disorders do not usually forget all of their personal history and their identity, although memory loss of this degree of severity occurs in rare instances in patient