16. Two full-adder implementations are presented in Figure la &1b Sum CinT Sum Cin (a) 1 3-in XOR, 3 2-in AND, and 1 3-in OR. (b) 2 2-in XOR, 2 2-in AND, and 1 2-in OHR Figure 1: Two different implementations of a full-adder (a) (3 Points) Prove that these two implementations are functionally equivalent using Boolean b) (1 Point) Which one of the two full-adder implementation above would you choose for (c) (1 Points) For the implementation you chose, convert the full-adder to a full-subtracter theorems. (Hint: Consensus) your design? Justify your choice. assuming negative numbers are represented in 2's complement