A $4-$month, $9$ percent note payable that is paid on maturity would incur total interest of:

$3$ percent because the note is only for a third of a year, and $\frac{1}{3}$ of $9$ percent is $3$ percent.

$\frac{41}{2}$ percent because the note is for half a year.

There would be no interest on the note because it was held for less than a year.

$9$ percent because that is the stated rate of interest on the note.