Final answer:
The assignment board is of least assistance in the supervision of a specific internal audit engagement, as it does not provide the detailed progress updates needed for effective supervision, unlike time budgets, time reports, and weekly status reports.
Step-by-step explanation:
The question asks which tool is of least assistance in the supervision of a specific internal audit engagement. The four options presented are time budget, time report, weekly status report, and assignment board. Of these, the assignment board is the least helpful for supervising a specific engagement. While an assignment board is useful for managing multiple projects and visualizing the allocation of resources, it does not provide the granular detail and updated progress information usually required for effective supervision of a specific engagement compared to the other tools.
A time budget helps in planning how much time should be spent on an engagement, and a time report offers insight into the actual time spent on various tasks. Meanwhile, a weekly status report provides ongoing updates on the progress of the engagement, which is crucial for supervision and addressing any issues in a timely manner. Therefore, in the specific context of supervising an individual internal audit engagement, the assignment board might be considered the least directly useful tool.