Final answer:
Auditors are least likely to use the work of a specialist in the determination of the existence of a complex financial instrument, as this task can be performed through traditional audit procedures.
Step-by-step explanation:
The student's question pertains to identifying in which area auditors are least likely to use the work of a specialist. Among the given choices:
- Determining the value of complex financial instruments.
- Assessing control risk for clients using complex derivatives for hedging.
- Determination of the existence of a complex financial instrument.
- Valuing an equity investment that must be valued using a complex valuation model.
Auditors are most likely to require the expertise of specialists in the areas involving complex valuations and assessments, such as the first, second, and fourth options. The third option, determination of the existence of a complex financial instrument, is primarily focused on confirming whether the item exists on the entity's balance sheet, rather than requiring a nuanced valuation or risk assessment. This is a task auditors can often perform through traditional audit procedures without the need for specialist input.