Devon earns a base salary of $600.00 per month, plus a 4% commission on his sales. Last month he brought in $15,000.00 in sales. Write an expression to represent his total compensation and calculate how much his total compensation was.

A) .04(600 + s) ; $624
B) 600 + .4s; $6,600
C) .4(600 + s); $6,240
D) 600 + .04s; $1200​