Red Insurance Company took out a mortgage loan of $400m on August 1, 2020 to construct an apartment complex and used the Head Office building and land as the security for the loan. Each month subsequent to the issue of the mortgage, a payment of $400,000 was paid to the mortgagor. You are in charge of the current year audit for Red Insurance Company, which has a balance sheet date of December 31, 2020.

c. Prepare a memo to the management of Red Insurance explaining the substantive procedure and the appropriate audit evidence required in order to verify the issue of the mortgage, the balance in the mortgage and interest payable accounts at December 31, 2020, and the balance in interest expenses for the year 2020.