Consider the function f(a,b,c)=a'b' + ac. Derive a circuit for f that (a) Uses only 2-to-1 multiplexers. (b) Uses a 4-to-1 multiplexer (and additional gates if necessary) with the help of the truth table. (c) Uses a 4-to-1 multiplexer (and additional gates if necessary) with the help of the Shannon's expansion theorem