3. We wish to design and Implement a 2-bit binary adder that adds (not multiplies) two numbers: X (2-bits) and Y (2-bits). X-Xi Xo and Y-Y Yo We want to explore three design alternatives: (a) Using only Full Adders, Half-Adders and AND gates. Draw a block diagram. 15pts. (b) Using logic gates. First draw a truth table for the 4-input, 3-output logic function. Then minimize each output using K-map and draw an implementation. 25pts.] (c) Using three 4:1 multiplexers and any other gates you wish. 115pts. (d) Which of these designs will you prefer to use and why? [5pts. Draw your diagrams clearly