According to the passage, what condition is responsible for many of the diseases of the old? A. Their trouble in remembering recent events B. The blood vessels that have becom
According to the passage, what condition is responsible for many of the diseases of the old?
A. Their trouble in remembering recent events
B. The blood vessels that have become thickened and constricted
C. The rigid and inflexible joints between the bones
D. The worn - out nerve cells and muscle- fibers