Answer:
a. Dec 31 Fees Earned 100 Rent Revenue 25 Income Summary 125
Explanation:
The closing entry to close the fees earned and the rent revenue is shown below
On December 31
Fees Earned  $100
Rent Revenue $25
   To Income Summary $125
(Being revenue account closed)
For closing this entry we debited the revenue account and credited the income summary account so that the proper posting could be done