A savings account compounds interest, at a rate of 25%, once a year. Eve puts $500 in the account as the principal. How can Eve set up a function to track the amount of money she has? (1 point)
Select one:
a. A(x) = 500(25)x where 25 is the interest rate
b. A(x) = 500(.25)x where .25 is the interest rate
c. A(x) = 500(1 + 25)x where 25 is the interest rate
d. A(x) = 500(1 + .25)x where .25 is the interest rate