If the function $g(x) = \left\{ \begin{array} {1 1} k \sqrt{x+1} , & \quad 0 \leq x \leq 3 \\ mx+2,& \quad 3 < x \leq 5 \end{array} \right. $ is differentiable , then the value of $k+m$ is :

Question

$\begin{array}{1 1} 4 \\ 2 \\ \frac{16}{5} \\ \frac{10}{3} \end{array} $