An entry debiting prepaid property taxes and crediting property tax expense is needed at the balance sheet date when prepayments are initially recorded in an expense account.
This adjusting entry defers expense recognition to the future period in which the property taxes apply.

The retention and maintenance of internal audit engagement records, including the period of time they must be kept, is governed by the internal audit activity's policies and procedures. These policies provide guidance on record retention consistent with organizational requirements, legal and regulatory obligations, and professional standards.
The charter (Option A) defines purpose, authority, and responsibility but does not detail document retention.
The annual plan (Option B) outlines engagements but not recordkeeping. The quality assurance and improvement program (Option D) addresses continuous improvement and compliance with standards, not retention guidelines.
Therefore, the correct source for document retention requirements is internal audit policies (Option C).
Reference:
IIA Standards - Standard 2330: Documenting Information; Implementation Guide 2330.

If collection time is 2 days, and average daily receipts are US $ 100,000, the average cash balance will increase by I. $200,000 if the bank's system is adopted At a 6% interest rate, US $200,000 will generate US $12,000 of interest revenue annually. The US $500 monthly charge by the bank will result in an annual expense of US $6,000. Thus, the net annual benefit is US $6,000 $12,000 - 6,000).