On December 1, year 1, Newton Corporation incurs a 15-year $300,000 mortgage liability in conjunction with the acquisition of an office building. This mortgage is payable in monthly installments of $3,600, which include interest computed at the rate of 12% per year. The first monthly payment is made on December 31, year 1. The portion of the second monthly payment made on January 31, year 2, which represents repayment of principal is: a $600. b $606. c $3,600. d $2,994