One way to solve is by going through each of the answers and plugging in x or y. I did this with each of them and the only one that came back correct is A: y=6x.
This is because when you look at the X column, anytime you plug in one of the numbers, such as 4, into the equation A gives you, it equals the number in Y.
Y=6(4)
Y= 24
Y=6(6)
Y=36
And so on.
Hope this helps :)