Which of the following relations is a function? A. (5, 11), (-9, 2), (-1, 8), (-6, 11) B. (11, 5), (2, -9), (8, -1), (11, -6) C. (-1, 11), (-9, 2), (-1, 8), (-9, -6) D. (5, 11), (-9, 2), (-1, 8), (-1, -6)

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams 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 ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18