Asset retirement obligations are estimated to be $250k at the origination. The entry to record accretion expense at the end of the asset's second year is:

a) Debit Accretion Expense $125k, Credit Asset Retirement Obligations $125k
b) Debit Asset Retirement Obligations $125k, Credit Accretion Expense $125k
c) Debit Accretion Expense $250k, Credit Asset Retirement Obligations $250k
d) Debit Asset Retirement Obligations $250k, Credit Accretion Expense $250k