Which table shows a proportional relationship between x and y?

x 2 3 4 5
y 7 9 11 13


x 3 6 8 10
y 12 15 18 20


x 3 7.5 15 20
y 1 2.5 4 6


x 1 2 7 8
y 0.5 1 3.5 4