Polynomial Long Division

The total number of notebooks sold from 2010 to 2015 at Charlie's store is given by the function $N(x) = 40x^3 + 8x^2 + 14824x + 33000$, while the number of kinds of notebooks in Charlie's store is given by the function $K(x) = 10x + 22$, where $x$ is the number of years since 2010. Which of the following expressions shows the average number of each kind of notebook Charlie has sold?