Jane receives a 10-year increasing annuity-immediate paying 100 the first year and increasing by 100 each year thereafter. Mary receives a 10-year decreasing annuity-immediate paying X the first year and decreasing by X/10 each year thereafter. At an effective annual interest rate of 5%, both annuities have the same present value. Calculate X.

a. 860
b. 864
c. 868
d. 872
e. 876