In given figure a silicon diode is carrying a constant current of $1 \mathrm{~mA}$. When the temperature of the diode is $20^{\circ} \mathrm{C}, \mathrm{V}_{\mathrm{D}}$ is found to be $700 \; \mathrm{mV}$. If the temperature rises to $40^{\circ} \mathrm{C}, \mathrm{V}_{\mathrm{D}}$ becomes approximately equal to
- $740 \; \mathrm{mV}$
- $660 \; \mathrm{mV}$
- $680 \; \mathrm{mV}$
- $700 \; \mathrm{mV}$