阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。
They already guide blind and disabled people; now dogs are to be trained to help people with dementia（痴呆） or Alzheimer's．Alzheimer's can make people confuse night and day or forget basic things such as washing or drinking enough water．
The dogs will be trained to respond to sound triggers（触发器） in the home that cause them to perform tasks．The duties will include reminding their owners to take medicine, as well as encouraging them to eat, drink and sleep regularly．
