Which word problem has the greatest rate of change?

Sam makes $25 per hour as well as a $100 bonus each month working for his uncle.

Car company A rents cars for $20 per day with an additional cost of $.75 per mile.

Justin started with $10 in savings and is adding an additional $35 every month.

Laney had $250 in her savings account at the beginning of the month and $260 at the end of the month.