Which of the following is considered a major factor in early onset Alzheimer's?

A) diet
B) stress
C) mental acuity
D) heredity

Heredity is considered a major factor in early onset Alzheimer's. People who inherit certain genes have a higher risk of developing the disease at a younger age. However, early onset Alzheimer's is relatively rare, accounting for less than 5% of all cases. Diet, stress, and mental acuity have been linked to overall brain health but are not considered major factors in early onset Alzheimer's.