2-to-1 multiplexers with an active high output and active high enable are to be used in the following implementations: (a) Show how to implement a 4-to-1 multiplexer with an active high output and no enable using two of the 2-to-1 MUXes and a minimum number of additional gates.
(b) Repeat part (a) for a 4-to-1 multiplexer with an active low output.
(c) Repeat part (b) assuming the output of the 2-to-1 MUX is 1 (rather than 0) when the enable is 0.