Final answer:
Auditing standards mandate that auditors must report in writing about significant deficiencies and material weaknesses in internal control that they discover during an audit. Not all deficiencies are required to be reported, only those that are significant or indicate a material weakness. Options B, C, and D are incorrect because they imply only one type of issue should be reported.
Step-by-step explanation:
Auditing standards require auditors to communicate in writing about significant matters regarding a company's internal control system. More specifically, auditors must report in writing about both significant deficiencies and material weaknesses they have found during the audit. Significant deficiencies are less severe than material weaknesses but still important enough to merit attention from those charged with governance. Material weaknesses, on the other hand, represent a more serious flaw in the internal control system, where there is a reasonable possibility that a material misstatement of the financial statements will not be prevented, or detected and corrected, on a timely basis.
According to the standards set by bodies like the American Institute of Certified Public Accountants (AICPA), option A is not correct because not all identified deficiencies are required to be communicated in writing, only those that rise to the level of significant deficiencies or material weaknesses. Similarly, options B, C, and D are incorrect because they suggest only one category either significant deficiencies or material weaknesses should be communicated in writing, whereas both should be included in the auditor's written communication to management and those charged with governance.