The monthly cost of driving a car depends on the number of miles driven. Julia found that in October it cost her $300 to drive 400 mi and in July it cost her $450 to drive 700 mi. Express the monthly cost C as a function of the distance driven d assuming that a linear relationship gives a suitable model. ? Group of answer choices C = 0.5d – 100 C = –100d + 0.5 C = 0.5d + 100 C = 100d – 0.5 C = 2d + 100