单选题：Memory Reduction　　It is common for older people to forget th

　Memory Reduction　　It is common for older people to forget things．Now an American study has found that memory starts to fail when we are young adults．People younger than thirty years of age usually do not know that they are starting to forget information．But scientists from the University of Michigan say the loss of memory usually has already started．
　　Researchers say people do not observe this slow reduction in mental ability until the loss affects their everyday activities．
　　Denise Park led the new study．She directs the center for Aging and Cognition at the Institute for Social Research at the University of Michigan．Her team studied more than 350 men and women between the ages of twenty and ninety years．The study identified people in their middle twenties with memopf problems．
　　She says young adults do not know they are forgetting things because their brains have more information than they need．
　　But she says that people in their ten ties and thirties are losing memmT at the same rate as people in their sixties and seventies．
　　Ms．Park says people between the age of sixty and seventy may note the decrease in their mental abilities．The), begin to observe that they are having more trouble remembering and learning new information．
　　The study found that older adults are more likely to remember false information as being true．For example，they remembered false medical claims as being true．Younger people remembered hearing the information．But they were more likely to remember that it was false．Ms．Park is now using modern imaging equipment to study what happens in the brains of people of different ages．She is studying what parts of the brain older adults use for different activities compared to younger adults．Ms．Park says mental performance is a direct result of brain activity and brain structure．She says keeping the brain active is important．She says older people should take part in activities that keep their brain active．These include being a member of a book—reading club，seeing and discussing plays and concerts and playing game that use the mind。She hopes future Studies will identify ways to improve the operation of our aging minds．根据以上材料回答下面问题：The passage is meant to reveal the decrease in mental ability of the young adults as well of the older adults． A．Right
B．Wrong
C．Not mentioned