Q$8.$ For the ideal class$-$B MOSFET power amplifier circuits in Figure Q$8.$ Assume that the input signal is a sinusoidal signal with zero offsets and MOSFETs are ideal $($threshold voltage of $M_n=0,$ and the threshold voltage of $M_P=0).$

$($a$)$ Calculate the quiescent power dissipation $P_{DC}$ and the worst$-$case MOSFET current $($IC$-$MAX$)$ of the MOSFET.

A$.0W,2A$

B$.40W,4A$

C$.40W,2A$

D$.0W,4A$

$($b$)$ Suppose the output is $20$ V peak$-$to$-$peak $(7\mathrm{.}07$ Vrms $).$ Obtain the efficiency $().$

A$.19\mathrm{.}6\%$

B$.39\mathrm{.}2\%$

C$.50\%$

D$.78\mathrm{.}5\%$