The table below shows the amount of money, in hundreds of dollars, elliot has saved after different numbers of years:

years (x) 1 2 3 4 5 6
money (y) (hundreds of dollars) 15 30 45 60 75 90

identify the function that represents elliot's savings and the amount that elliot will have saved in 9 years.
(a)y = 15x, in 9 years he will have saved $13,500
(b)y = x + 15, in 9 years he will have saved $2,400
(c)y = 6x, in 9 years he will have saved $5,400
(d)y = x + 90, in 9 years he will have saved $9,900