Memory impairment is most likely to occur in:

Answer is A (Down's syndrome) Down Syndrome is associated with memory impairment. Adults with trisomy 21 (Down's) consistently develop the neuropathologic hallmark's of Alzheimer's disease of they survive beyond 40 years of age - Harrison 's The most noble aspect is down's syndrome is marked mental retardation, relatively poor expressive language and impaired verbal sho term memory' - Child and Adolescent Psychiatry