For a fixed number of processes, SJF scheduling algorithm: a. Minimize average turn-around time. O b. Only Maximizes CPU throughput and Minimize average response time. O c. Only Minimize average waiting time and Minimize average turn-around time O d. Maximizes CPU throughput e. Minimize average waiting time. What events occur to cause a process to change states? a. a process gets blocked waiting for input O b. Any of these O c. the scheduler chooses another process to be run O d. process changes from blocked to ready state upon completion of its 1/0 O e. the scheduler chooses this ready process to run