Final answer:
The correct answer is that a debit to Fund Balance--Unassigned is required when revenues are less than expenditures in governmental fund accounting. This represents a budget shortfall or deficit situation.
Step-by-step explanation:
The student's question pertains to government fund accounting, specifically the impact of revenue and expenditure variances on Fund Balance--Unassigned at year-end closing. When operating statement accounts are closed, if revenues are less than expenditures, a debit to Fund Balance--Unassigned would be required.
This is because the Fund Balance reflects the net financial resources available to the government and would decrease in the case of a deficit. This situation mirrors the concept of an annual budget shortfall, which occurs when tax revenue is insufficient to cover government spending.