Answer:
Usually, we use the "Income Summary" account to close the Income Statement accounts such as revenues and expenses.
First, close the revenue account by debiting it:
(DR) Service Revenue $450,000
(CR)       Income Summary    $450,000
Then, close the expenses accounts by crediting them:
(DR) Income Summary $407,000
(CR)        Salaries Expense       $350,000
(CR)        Rent Expense              $17,500
(CR)       Depreciation Expense   $35,000
 (CR)      Interest Expense             $4,500
Finally, close the Income Summary account to Retained Earnings.
The balance of the Income Summary is a credit balance of $43,000
(credit of $450,000 less debit of $407,000)
So, to close the account we have to debit it.
(DR)  Income Summary      $43,000
(CR)               Retained Earnings          $43,000