Answer and Explanation:
The Journal entry is shown below:-
On December 31, 2018
Unearned rent revenue Dr, $12,600 ($21,600 × 7 months ÷ 12 months)
To Rent Revenue $12,600
(Being unearned rent is recorded)
Here for recording unearned rent, we debited the unearned rent revenue as it decreased the liabilities and we credited the rent revenue as it increased the revenue and the same is to be considered