Final answer:
The correct sentence completion is 'Supervisor, Training Officer, 30 days before,' indicating the roles and timeframe needed for reporting a probationary employee's substandard performance.
Step-by-step explanation:
Probationary periods serve as a buffer on the buyer's side of the labor market, allowing the employer to assess a new employee's performance without committing to long-term employment. This period often comes with a caveat for the employee - a risk of dismissal for any or no reason and occasionally lower wages during the trial period. Regarding the missing parts in the provided sentence, the option that logically completes it is: A. Supervisor, Training Officer, 30 days before. This indicates that if a probationary employee's performance is not meeting expectations, the Supervisor and Training Officer should collaborate to provide the necessary documentation to the Fire Chief about the employee's performance at least 30 days before the end of the probationary period. It is important that these roles are clearly defined within a company's policies and that they work in step to ensure probationary periods serve their intended purpose.