On May 1, 2011, Giltus Advertising Company received $1,500 from Julie Bee for advertising services to be completed April 30, 2012. The cash receipt was recorded as unearned fees. At December 31, 2011, $500 of the fees had been earned. The adjusting entry on December 31, 2011 should include:
a) A debit to Unearned Fees for $500
b) A credit to Unearned Fees for $500
c) A credit to Earned Fees for $1,000
d) A debit to Earned Fees for $1,000