A $2\mathrm{.}0$ kg block slides down a $1.36$ m ramp with unknown coefficient of friction, and the ramp makes an angle of $36\mathrm{.}9$ with respect to the horizontal. If the block has a speed of $1\mathrm{.}0$ m$/$s at the top of the ramp and a speed of $3\mathrm{.}0$ m$/$s at the bottom, then what is the net work done on the block by external forces as it slides down?

$($a$)+16$ J

$($b$)+8\mathrm{.}0$ J

$($c$)0$ J

$($d$)-8\mathrm{.}0$ J

$($e$)-16$ J