Which one of the following transfer functions, upon a unit step change in disturbance at $t=0$, will show a stable time domain response with a negative initial slope (i.e., slope at $t=0$):

1. $G\left ( s \right )=\frac{1}{s+1}-\frac{2}{s+4}$
2. $G\left ( s \right )=\frac{1}{s+1}+\frac{2}{s+4}$
3. $G\left ( s \right )=\frac{1}{s+1}+\frac{2}{s-4}$
4. $G\left ( s \right )=\frac{1}{s-1}+\frac{2}{s-4}$