In the circuits below, transistors are characterized by $Vt=2V$ for the NMOSFET and $Vt=-2V$ for the PMOSFET, $k_n^{\text{'}}(\frac{W}{L})=1m\frac{A}{V^2}$ for the NMOSFET and $k_p^{\text{'}}(\frac{W}{L})=1m\frac{A}{V^2}$ for the PMOSFET, and $=0$ for both types of MOSFET. Find the labeled voltages $V_1$ through $V_7.$

$($c$)$