The threshold voltage for each transistor in the figure is $2 \mathrm{V}$. For this circuit to work as an inverter, $V_{i}$ must take the values
- $-5 \mathrm{~V}$ and $0 \mathrm{~V}$
- $-5 \mathrm{~V}$ and $5 \mathrm{~V}$
- $-0 \mathrm{~V}$ and $3 \mathrm{~V}$
- $3 \mathrm{~V}$ and $5 \mathrm{~V}$