Sam is a waiter at a local restaurant where he earns wages of $5 per hour. Sam figures that he also earns about $3 in tips for each person he serves. Sam works 6 hours on a particular day.If n represents the number of people Sam serves that day, which of the following functions could Sam use to figure E, his total earnings for the day?

A - E(n)=3n+30
B- E(n)=3n
C- E(n)=5n+18