Answer:
Debit unearned revenues for $400
Step-by-step explanation:
Adjusting entries are journal entries made to record revenues and expenses accounts. These entries are made at the end of an accounting cycle.
Payment received for services on December 1 that was recorded as a liability = $1,000
Amount earned by the end of the year = $400
Therefore,
adjusting entry: Debit unearned revenues for $400 so that expenses matched to the accounting period in which the revenue paying for them is earned.