Amount Financed(P) = $ 128,000
Time = 15 year
Rate of interest= 5.05%
Amount after 15 years translates to,

Rose and Andrew has taken four points to lower their rate to 4.81% .
Amount after 15 years translates to, if rate of interest is 4.83 %
Cost of four points = 268,009.890 - 259,713.0404
= $8296.8496
To write 8.57 as a fraction you have to write 8.57 as numerator and put 1 as the denominator. Now you multiply numerator and denominator by 10 as long as you get in numerator the whole number.
8.57 = 8.57/1 = 85.7/10 = 857/100
And finally we have:
8.57 as a fraction equals 857/100
The answer you want is going to be A.
Hope it helps.