Assume that the operation times for the major functional units of a single-cycle machine are the following: memory units: 200 ps ALU and adders: 100 ps register file (read or write): 50 ps Assuming that mux, control unit, PC accesses, sign extension unit, and wires have no delay, which of the following implementations would be faster and by how much? a) An implementation in which every instruction operates in 1 clock cycle of a fixed length. b) An implementation where every instruction executes in 1 clock cycle using a variable length clock, which for each instruction is only as long as it needs to be (critical path). (Such an approach is not terribly practical, but it will allow us to see what is being sacrificed when all the instructions must execute in a single clock cycle of the same length.)