Which of the Following Represents the Best Description of the Projected

Which of the following represents the best description of the projected benefit obligation at any balance sheet date?

A) Service cost to date + interest cost to date + unrecognized gain or loss at the balance sheet date
B) Service cost to date + prior service cost to date + unrecognized gain or loss at the balance sheet date
C) Service cost to date + interest cost to date - amortized prior service cost - actual return - benefits paid to date
D) Service cost to date + interest cost + net total actuarial gain or loss + prior service cost to date - benefits paid to date