Megan is going on a long-distance road trip. If y is the total number of miles driven, and x is the number of hours driven after reaching 10 miles, which statement best describes the rate of change in the distance traveled?
a. For every 10 hours, she will drive 68 miles.
b. For every two hours, she will drive 58 miles.
c. For every hour, she will drive 68 miles.
d. For every hour, she will drive 58 miles.