Consider the following three statements regarding Process State Transitions:

Statement I: A process transitions from the 'Running' state to the 'Ready' state when a timer interrupt occurs in a preemptive scheduling system.

Statement II: A process transitions from the 'Running' state to the 'Waiting' (or Blocked) state when it issues an I/O request.

Statement III: A process can transition directly from the 'Waiting' state back to the 'Running' state the moment its I/O operation is completed.

Which of the statements given above are correct?