Craig has a job waiting tables where he earns $3.45 per hour plus tips. Craig earned $73.68 in tips during his shift yesterday.

If x represents the number of hours Craig worked yesterday, which of the following equations can be used to find the amount of money Craig earned yesterday?
A. y = 3.45x - 73.68
B. y = 73.68x + 3.45
C. y = 3.45x + 73.68
D. y = 73.68x - 3.45