C.3 (a) A ROM is used to implement the Boolean functions given below. Yo = A.B.C.D+ A.B.C.D + A.B.C.D Y = (A + B).(A + B+C) Y = (13, 15) (1) Find the maximum size of the ROM required. (1 mark) (ii) Implement the ROM circuit using a 4-to-16 active high decoder. Show the connections and labels clearly. (5 marks) (b) Implement a combinational logic circuit design of a full adder by using encoder and 2- inputs NAND gate only (4 marks)