On December $1,$ Oren Marketing Company received $$5,400$ from a customer for a $2-$month marketing plan to be completed January $31$ of the following year. The cash receipt was recorded as unearned revenue. The adjusting entry for the year ended December $31$ would include:

Multiple Choice

a credit to Services Revenue for $$3,600.$

a debit to Services Revenue for $$3,600.$

a debit to Unearned Revenue for $$2,700.$

a credit to Unearned Revenue for $$1,800.$

a debit to Services Revenue for $$5,400.$