On October 1, Goodwell Company rented warehouse space to a tenant for $1,600 per month and received $8,000 for five months' rent in advance on that date, with the lease beginning immediately. The cash receipt was credited to the Unearned Rent account. The company's annual accounting period ends on December 31. The Unearned Rent account balance at the end of December, after adjustment, should be: Multiple Choice O O $3,200 O $4,800 $8,000 O $1,600. O O $6,400