Which of the following statements about Alzheimer's disease are true?

The first statement is correct. Onset is usually after 65 years of age. Second statement is incorrect, long-term memory gets affected in advanced stages only. Third statement is also incorrect as senile plaques contain amyloid bet (Ab) and not tau proteins. The last statement can be argued upon. Alzheimer's disease is usually described as disease of temporal and parietal lobe and MRI usually shows atrophy in temporal and parietal lobe. Although we must remember that frontal coex does get involved in the advanced phases