Option A looks correct!
Because, before using any resource we have to request OS for that particular resource. Once request received, OS will check for its availability, and if it's available then will grant permission to access that resource. If not then, OS forces process to wait until resource become free/available.
And once permission is granted, process will use requested resources and upon completion will release all connections with resources so that they become available for other process.
The importance for sending a request before using it:
If the resource is not available when it is requested, the requesting process is forced to wait. In some operating systems, the process is automatically blocked when a resource request fails, and awakened when it becomes available. In other systems, the request fails with an error code, and calling process waits a little while and try again.
Here, only option A has sequence of Request, Use & Release. Hence, A is correct.
