Acceleration of 12 meters/secondsecond2 car mass 1515 kilograms to reach acceleration of 15 meters/second 2

I guess the following digits are only the given but I'm assuming that this is the question:
A car maker has designed a car that can reach a maximum acceleration of 12 meters/second^2. The car’s mass is 1,515 kilograms. Assuming the same engine is used, what should the car’s mass be if the car maker wants to reach an acceleration of 15 meters/second^2? 

Then the choices are the following:
A 1,212 kg
B 1,335 kg
C1,466 kg
D 1,515 kg
E 1,894 kg

The answer is E.1,894 kg.

Solution:
USE ratio and proportion
m1/a1=m2/a2
1515kg/12meter per seconds=(unknown mass)/15 meters per seconds
let n be the unknown mass
1515(15)=12(n)
1515(15)/12=n
n=1,894 kg

Are a.larger

Sorry i don’t know what to do