The following incomplete (columns have missing amounts) pension spreadsheet is for Maguire Corporation. Plan Assets PBO (610) Prior Net Service (Gain) Pension Cost Loss Expense Cash 91 95 Net Pension (Liability)/Asset (34) (4) ($ in millions) debit (Credit) Beginning balance Service cost Interest cost Expected return on assets Gain/loss on assets Amortization of: Prior service cost Net gain/ loss Loss on PBO Contributions to fund Retiree benefits paid Ending balance (17) (36) 36 (89) 65 (65) 352 (702) 87 111 (350) What was the prior service cost at the beginning of the year? Multiple Choice $87 million. $91 million o $104 million c $70 million