Final answer:
Without context, the time frame for reporting the status of a complaint can vary, but referenced historical data suggests 45 days as a reported average time, which is option D.
Step-by-step explanation:
The question you're asking doesn't provide enough context for a definitive answer, as the required time frame for an investigative unit to report the status of a complaint to the Director can vary depending on the organization's policies and the jurisdiction's laws.
However, using the reference provided, which mentions an average reported time of forty-five days for a certain scenario (Willcocks 1913, 1:301), we could lean towards option D) 45 days as the most likely answer within that specific historical context.
It's important to note that for real-world applications, you would need to consult the specific regulations or guidelines of the organization or legal body relevant to the investigation to obtain the accurate time frame.