Answer:
a. an age-based double standard.
Step-by-step explanation:
An age-based double standard takes place when an old person's memory fails and people consider it to be less serious than in the case of a young person. This attribution happens because people assume that an older person has his/her mental health more deteriorated (whether in memory, concentration, etc.) than a young person, and it is somehow naturally expected to be that way. In this case, Alice's grandchildren did not take notice of her granddaughter's episode but focus their attention on her instead because of her age.