Answer:
D. Marcus rent a car for 5 days
Step-by-step explanation:
You can solve this by simply plugging the answer choices into the variable d for both equations and comparing the total costs.
When you plug in 5 days you get:
Plan A
C = 30 x 5
C = 150
Plan B
C = 25 x 5 + 15
C = 140
The cost is less for Plan B in this case, so it is better to use Plan B when renting for 5 days.