$1)$ On December $31,2023,$ Mongo, Incorporated reported in its balance sheet a net loss of $$3$ million related to its pension plan. The actuary for Mongo at the end of $2024$ increased her estimate of future salary levels. Mongo's entry to record the effect of this change will include:

A$)$ A debit to loss$$OCI and a credit to PBO.

B$)$ A debit to PBO and a credit to loss$$OCI$.$

C$)$ A debit to pension expense and a credit to PBO.

D$)$ A debit to pension expense and a credit to loss$$OCI$.$