20 points!
which table shows a proportional relationship?

a:

b| 2 3 8 9 14
c| 4 6 16 18 28

b:

r| 2 3 4 5 6
s| 3 5 6 8 9

c:

p| 1 3 5 7 9
q| 3 7 11 15 19

d:

x| 1 2 3 4 5
y| 4 5 6 7 8