Three benchmarks (Programs) are used to assess the performance of 4 computers. The execution time results (in second) are given below: Computer A Computer B Computer C Computer D Bench 1 100 100 100 125 Bench 2 Bench 3 300 200 50 75 200 150 150 100 d- a- Compute the total execution time for each computer. b- Compute the arithmetic average of execution time for each computer. Sort the computers A-D depending on their performance from the best to the worst. Given the Bench 1 has 100000000 (10") instructions, compute the rate (MIPS) of computer A.