Final answer:
The typical onset of Alzheimer's disease is predominantly characterized by memory loss, but also includes confusion, problem-solving difficulty, and changes in personality. The correct option is (1).
Step-by-step explanation:
The most typical example of the onset of Alzheimer's disease is memory loss. This symptom is characterized by disruptive memory issues that interfere with daily life.
Alzheimer's disease also includes other symptoms, such as confusion about time or place, difficulty planning or executing tasks, poor judgment, personality changes, and problems with sense of smell.
These symptoms must be severe and persistent to indicate Alzheimer's, as they can sometimes be confused with normal aging effects. Additionally, on a cellular level, Alzheimer's disease involves the development of amyloid plaques and neurofibrillary tangles in the brain, leading to loss of neuron synapses and ultimately neuron death.