Sam is hired at a small sales company. his monthly pay is calculated by the equation p=150s + 500. in this calculation s= the number of sales P= Sam's pay in dollars witch statement is true? a)Sam earns 150 for each sale he makes b)Sam earns 500 for each sale he makes. c) sam earns a base salary of 650 each month d) the verticle is (0, 150).