Dan's grandmother started a college savings account for him when he was born. The account earns 2.5% interest compounded annually. If you know the account's value after 15 years is A, which expression tells you the account's value after 18 years?

a) 1.025^3 times A
b) 0.025^3 times A
c) 0.025 +3A
d) 3 times 0.025 + A
e) 3 times 1.025 + A
f) 3 times 1.025^A

a) 1.025^3 times A