Final answer:
A significant decline in the market price of a corporation's stock after the fiscal year-end but before the auditor's report is issued typically does not require disclosure in the financial statements, as it pertains to events arising after the fiscal year.
Step-by-step explanation:
The event that occurred after the end of the fiscal year under audit but prior to issuance of the auditor's report that may not require disclosure in the financial statements is C) a significant decline in the market price of the corporation's stock. Events that provide additional information about conditions that existed at the end of the fiscal year and that could affect the financial statements typically require disclosure or adjustment. However, certain events that indicate conditions that arose after the fiscal year-end—such as a decline in market price of stock—do not typically affect the financial statements being audited, as they do not represent the company's conditions at the balance sheet date. Hence, while these events are of interest to investors and stakeholders, they are not required to be disclosed in the financial statements for the fiscal year that has ended.