Tony and Ricky spend a certain amount of money from their accounts each week at a pet shelter.

The table shows the relationship between the amount of money (y) remaining in Tony's account and the number of weeks (x):

Function 1:
Number of Weeks
(x) Amount Remaining (dollars)
(y)
1 30
2 24
3 18
4 12

The equation shows the relationship between the amount of money, y, remaining in Ricky's account and the number of weeks, x:

Function 2:
y = −7x + 30

Which statement states and explains which function shows a greater rate of change?

a. Function 1, because Tony spends $6 each week and Ricky spends −$7 each week

b. Function 2, because Ricky spends $7 each week and Tony spends $6 each week

c. Function 1, because Tony spends $18 each week and Ricky spends $23 each week

d. Function 2, because Ricky spends $30 each week and Tony spends $18 each week