Step 1: Question Interpretation.
The query concerns the function responsible for verifying the accuracy of established benchmarks, specifically performance evaluation against set criteria.
Step 2: Option Analysis.
- Directing: This function focuses on motivating and guiding personnel, excluding the assessment of standard accuracy.
- Organising: This function pertains to resource and task arrangement, not direct standard judgment.
- Planning: This function establishes the standards but does not involve their direct evaluation.
- Controlling: This function entails performance monitoring, comparison against standards, and implementation of corrective measures, thereby ensuring standard accuracy.
Step 3: Determination.
The accurate response is Controlling, as it encompasses the evaluation of performance against predetermined standards.
Final Determination: \[\boxed{\text{Controlling is the correct response.}}\]