Ted researched the price of airline tickets and discovered a correlation between the price of a ticket and the number of miles traveled. After recording his data on a scatter plot, he determined the equation for the line of best fit is y = 300 + 0.45x. What does 300 represent in the equation?
A: the number of miles traveled at 0.45 per mile
B: the maximum number of miles allowed at 0.45 per mile
C: the cost of the ticket when the number of miles equal 0
D: the cost of the ticket when the number of miles equal 45