Changed the graph to a table so you could see what I did to find slope and the difference. Attached work.
Answer: 337 or 337^2 ~ 142129
Hope this helps :)
The answer to your question is the first option, which includes the points (3,6) and (5,10).
We know that this is the answer because the two numbers, if set up in fractional form, are proportional.
Additionally, the two points like on the same line in the graph.
Hope this helps!!