$(5$ pts $)13.$ A small block with mass $0\mathrm{.}200$ kg slides up a $36\mathrm{.}9$ incline from bottom to top, a distance of $2\mathrm{.}00$ m $.$ For this displacement of the block, what is the work done on the block by the normal force that the incline exerts on the block?

$($a$)$ zero

$($b$)+3\mathrm{.}1$ J

$($c$)-3\mathrm{.}1$ J

$($d$)+2\mathrm{.}4$ J

$($e$)-2\mathrm{.}4$ J

$($f$)$ none of the above

Please help me understand why this is zero. I thought it would exert work on the block due to the block having to go up the ramp.