What is the proper factor notation for calculating the present worth of a gradient series, given a gradient amount of $500, an interest rate of 2%, and the number of periods equal to 10?
a) P-$500(PIF 290, 10)
b) P-$500(GIP 296, 10)
c) P-$500(PIA 296, 10)
d) P-$500(PIG 296, 10)