Given function $f ( x ) = \left\{ \begin{array} { l l } - x ^ { 2 } - 2 a x - a , & x < 0 , \\ \mathrm { e } ^ { x } + \ln ( x + 1 ) , & x \geqslant 0 \end{array} \right.$ is monotonically increasing on $\mathbb { R }$ , then the range of $a$ is\\
A. $( - \infty , 0 ]$\\
B. $[ - 1,0 ]$\\
C. $[ - 1,1 ]$\\
D. $[ 0 , + \infty )$