When an installment note is structured as a "fully amortizing" loan with equal monthly payments $($such as a traditional mortgage$)$ the:

Multiple Choice

Portion of each payment allocated to interest expense is the same each month.

Sum of the monthly payments is equal to the amount of the installment note $($mortgage$).$

Difference between the sum of all monthly payments and the principal amount of the note constitutes interest.

Portion of each payment allocated to repayment of principal decreases each month as the mortgage is paid off.