Answer:
A bad idea, as A2 is not on the critical path.
Step-by-step explanation:
Critical path is a path which is the shortest path of doing the activity.
When an activity is in critical path, then there is a benefit of crashing it. Or if it is not the part of critical path then the benefit is to crash the activity and then apply the spare resources in some activity which is a part of critical path.
Thus, crashing A2 which is not a part of critical path and then not deploying the resources on to the activities of critical path will not provide for any benefit.
It is ultimately not a wise idea.