operating systems fast please

For a fixed number of processes. SJF scheduling algorithm: a. Minimize average waiting time. w O b. Only Minimize average waiting time and Minimize average turn-around time O c. Maximizes CPU throughput O d. Minimize average turn-around time. e. Only Maximizes CPU throughput and Minimize average response time. The producer consumer problem can be solved with process cooperation. Which one of the following statements is correct? a. When the buffer is full the consumer must wait b. When the producer is running the consumer must wait c. When the buffer is empty the producer must wait d. When in == out the consumer must wait If a scheduling algorithm always gives the printer to the process with the smallest print job. what can happen? a. circular wait b. starvation C. mutual exclusion d. printer lockup