The Monthly Cost of Driving a Car Depends on the Number

Multiple Choice

The monthly cost of driving a car depends on the number of miles driven. Julia found that in October it cost her $\$ 200$ to drive 300 mi and in July it cost her $\$ 350$ to drive 600 mi. Express the monthly cost C as a function of the distance driven d assuming that a linear relationship gives a suitable model.

A) $C=-50 d+0.5$
B) $C=-50 d-0.5$
C) $C=0.5 d+50$
D) $C=2 d+50$
E) $C=0.5 d-50$