$($c$)$ Realize the following function of four variables using:

$($i$)8$:$1$ Multiplexers and

$($ii$)4$:$1$Multiplexers.

$F=\frac{A}{b}ar\frac{B}{b}ar(C)D+A\frac{B}{b}ar(C)D+\frac{A}{b}ar(B)\frac{C}{b}ar(D)\frac{+}{b}ar(A)\frac{B}{b}ar\frac{C}{b}ar(D)+\frac{A}{b}ar\frac{B}{b}ar\frac{C}{b}ar(D)$