On December 1, 2020, Sheridan Corporation incurs a 15-year $400000 mortgage liability in conjunction with the acquisition of an office building. This mortgage is payable in monthly installments of $4800, which include interest computed at the rate of 12% per year. The first monthly payment is made on December 31, 2020. The portion of the second monthly payment made on January 31, 2021, which represents repayment of principal is: $800. $4800. $808. $3992.