Figure $5\mathrm{.}7$: Refer to Questions $2$ and $3.$

Which of the following Boolean functions is implemented by the CMOS pass$-$logic gate

schematic shown in Fig$\mathrm{.}5\mathrm{.}7?$

$($a$)Y=\frac{x_1}{b}ar(x_3)(x_2\frac{+}{b}ar(x_2)x_4)\frac{+}{b}ar(x_1)x_2(x_3\frac{+}{b}ar(x_3)x_4)\frac{+}{b}ar\frac{x_1}{b}ar(x_2)(\frac{x_3}{b}ar(x_4)\frac{+}{b}ar(x_3)).$

$($b$)Y=x_1(x_2\frac{+}{b}ar\frac{x_2}{b}ar\frac{x_3}{b}ar(x_4))\frac{+}{b}ar(x_1)(x_2\frac{+}{b}ar(x_2)x_3{x}_4).$

$($c$)Y=x_1{x}_2(x_3{x}_4\frac{+}{b}ar(x_3))\frac{+}{b}ar(x_1)x_2(\frac{x_3}{b}ar(x_4)\frac{+}{b}ar(x_3)x_4)\frac{+}{b}ar\frac{x_1}{b}ar(x_2).$

$($d$)Y=x_1[x_2\frac{x_3}{b}ar(x_4)\frac{+}{b}ar(x_2)(x_3\frac{+}{b}ar(x_3)x_4)]\frac{+}{b}ar\frac{x_1}{b}ar(x_2)x_4.$

$($e$)Y=x_1(\frac{x_2}{b}ar(x_3)x_4\frac{+}{b}ar(x_4))\frac{+}{b}ar(x_1)(x_2{x}_3{x}_4\frac{+}{b}ar\frac{x_2}{b}ar(x_3))$

$($f$)$ None of the above.

Which of the following is a complete set of redundant devices of the pass$-$logic gate shown

in Fig$\mathrm{.}5\mathrm{.}7$

$($a$)$ M$1,$ M$2,$ M$19,$ M$13,$ M$14,$ M$23.$

$($b$)$ M$5,$ M$6,$ M$25,$ M$13,$ M$14,$ M$15,$ M$27.$

$($c$)$ M$3,$ M$4,$ M$21,$ M$23.$

$($d$)$ M$3,$ M$4,$ M$17,$ M$18,$ M$5,$ M$6,$ M$7,$ M$8,$ M$15,$ M$16,$ M$23,$ M$24.$

$($e$)$ M$3,$ M$5,$ M$6,$ M$7,$ M$8,$ M$20,$ M$13,$ M$14,$ M$15,$ M$16,$ M$23.$

$($f$)$ M$19,$ M$20,$ M$11,$ M$12,$ M$15,$ M$16.$