$1.$ Process aging is$?$ a$.)$ Decreasing the priority of a process each time the process gets to run b$.)$ Increasing the priority of a process if it sits in the ready state for a long time. c$.)$ decreasing the priority of a process as it gets older regardless of the queue d$.)$ increasing the priority of a resource if it becomes deadlocked $2.$Which scheduler does not risk starvation of the processes? a$.$ Shortest remaining time first scheduler b$.$ Round$-$robin scheduler c$.$ Shortest time first queues. d$.$ Priority scheduler $3.$ Process code loaded into memory can be executed by multiple threads. T or F $4.$ When a process executes a system call, what mode does the operating system enter? A$)$ Context mode B$)$ Services mode C$)$ Kernel mode D$)$ User mode