A used electronics store pays $50 for each cell phone, spends $15 refurbishing the phone, and sells the refurbished phone to a customer for $120. a. Write an expression in simplest form that represents the company's earnings (in dollars) from buying, processing, and selling cell phones. Use x to represent the number of cell phones they sell.
An expression is ( ) dollars.
b. What does the coefficient of the expression in part (a) represent?

A:the total number of phones the company sells

B:the amount (in dollars) the customer loses from each phone

C:the amount (in dollars) the company earns from each phone

D:the amount (in dollars) the company spends on each phone