A bank account contains $5,400 today. The account earns interest annually at a rate of 7%. The bank uses the equation a = 5,400(r)y to determine the amount of money in the account, a, after y years if no other deposits or withdrawals are made. To the nearest whole dollar, how much money will be in the account four years from now?
a) $4,039
b) $5,778
c) $6,912
d) $7,078