(1) Design a Full Adder (FA) and show the resulting Circuit Diagram implemented using AND, OR and XOR gates. 2) Use modular design to create a 4-bit adder (4b-Add) by using instances of the previously design FA in part (1). Show the corresponding circuit diagram (use block symbols to represent each FA) 3) Design a 4-bit wide 2-to-1 multiplexer (4b-2o1Mux) by using basic logic gates (AND, OR, NOT) and show the resulting Circuit Diagram (4) Using block symbols to represent the circuits you builtin part (2 and part 3) along with any additional components, show the resulting circuit diagram for your hexadecimal adder/subtractor (HEX-ADD SUB) Hints: a] Recall that a negative number needs to be transformed into corresponding 2's Complement (same as 1's complement plus one) b Nofice only "B" requires the 2's complement circuit, do not need it for number A