When α<β<ɤ then if follows last in first out scheduling. Here's the explanation :-
All the processes in the ready queue has the same initial priority ɤ. Their priority decreases at the same rate α(α<ɤ). Thus, the earlier the process enters the ready queue, the lower its priority will be.
Once the process with the highest priority(last-come compared to other process in the ready queue) is running, no other process in the ready queue will preempt it since its priority decreases at a lower rate (α<β<ɤ) than the priorities of those processes in the ready queue. But it will be preempted by any new coming process because the new process's priority is ɤ which is the highest possible priority.
So answer is Option B.