Kevin and Christy both saved money for their class trip. Kevin saved the same amount each week. The total amount that Kevin saved at the end of every two weeks is shown in the table below.
Christy's savings can be modeled by the equation , where is the total amount of money saved in weeks. Which statement correctly compares the rates at which Kevin and Christy saved money?

A
Christy saved $3\$ 3$3 per week more than Kevin.
B
Kevin saved $10\$ 10$10 per week more than Christy.
C
Christy saved $18\$ 18$18 per week more than Kevin.
D
Kevin saved $20\$ 20$20 per week more than Christy.