2] A digital computer has a common bus system for 8 registers (R1 R8) of 16 bits each. (a) How many selection inputs are there in each multiplexer? (b) What size of multiplexers are needed? (c) How many multiplexers are there in the bus? (d) Construct the common bus system with multiplexers; show their inputs and their selection variables (S0, S1). (e) Draw a diagram of a bus system, using three-state buffers and a decoder