Ok to see the difference of what they paid between those years you should look for the percentage change. To do this first you have to calculate the quotient between the 2019 value and the 2018 value: 3516/3200=1.099.
That number multiplied by 100 gives you the percentage of the rise:
1.099*100=109.875% so the price increased a 9.875%.
So the correct answer would be item A.