Answer:
B
Explanation:
To find the constant of proportionality between y and x, divide
for all given values of the chart. If you get the same number, then that is the constant. If they are all different numbers, then one does not exist for that function.
Using the method above, you should get:
Chart A = 2/5
Chart B = 1/5 (Correct Answer!)
Chart C = N/A
Hope this helps!