A)
Interest rate is 2,5% per year
That means that each year Sally's C.D. founds will be increased by a factor 1.025
Then, after 5 years, Sally's founds will be increased by a factor 1.025^5 = 1.1314, wich represents an interest rate of 13,14% (0.1314*5000 = 657.04 $) in five years.
B) Therefore, final C.D. worth at the end of the five year period is 1.1314*5000 = 567.04 $