The zener diode in the regulator circuit shown in the figure has a Zener voltage of $5.8$ volts and a Zener knee current of $0.5 \mathrm{~mA}$. The maximum load current drawn from this circuit ensuring proper functioning over the input voltage range between $20$ and $30$ volts, is
- $23.7 \mathrm{~mA}$.
- $14.2 \mathrm{~mA}$.
- $13.7 \mathrm{~mA}$.
- $24.2 \mathrm{~mA}$.