The first column is x while the second is y. To find rate, you divide y by x. If each row has the same outcome, it is proportional.
First row:
9.00÷2= 4.50
Second row:
22.50÷5= 4.50
Third row:
31.50÷7= 4.50
There is a proportional relationship based off of the values.
So B, yes there is a constant of proportionality of $4.50.