Final answer:
An auditor would be least likely to use an audit specialist for the existence of cash, as the verification of cash does not typically require the specialized knowledge that specialists provide for complex valuations or interpretations.Thus the correct option is a.
Step-by-step explanation:
An auditor would be least likely to use an audit specialist for the existence of cash. Audit specialists are usually employed for more complex judgments that require specialized knowledge or skills outside the realm of accounting and auditing standards. These complex judgments include the valuation of unique assets such as works of art, determining the value of oil and gas reserves, or interpreting complex laws and regulations. Cash, however, is a more straightforward asset to verify and typically does not require specialist knowledge to confirm its existence.