A combination of $1\:μF$ capacitor with an initial voltage $V_{c}(0)=-2\:V$ in series with a $100\:Ω$ resistor is connected to a $20\:mA$ ideal $dc$ current source by operating both switches at $t=0s$ as shown. Which of the following graphs shown in the options approximates the voltage $V_s$ across the current source over the next few seconds?