Which explanation matches the following runtime complexity?

T$($N$)=$k$+$T$($N$-1)$

$$Every time the function is called, k operations are done, and each recursive call lowers N by one fourth.

$$Every time the function is called, k operations are done, and the recursive call lowers N by k$.$

$$Every time the function is called, k operations are done, and the recursive call lowers N by $1.$

$$Every time the function is called, k operations are done, and each of the $2$ recursive calls reduces N by half.