Which of the following activities should be performed during the preparation for an inspection?

The correct choice emphasizes a proactive approach to inspection preparation. Determining the need for an inspection is crucial as it sets the foundation for what specific areas will require attention. By preparing sample containers in advance, inspectors ensure they have the necessary tools ready to collect samples during the inspection, which can greatly streamline the process and enhance the quality of data collected.

Reviewing existing files allows inspectors to familiarize themselves with prior inspection results, compliance history, and any previous issues that may need to be addressed. This background knowledge is vital for assessing current conditions and anticipating potential problem areas during the inspection itself.

In contrast, while the activities described in the other choices may also be important, they reflect actions that are either too reactive or related to post-inspection procedures rather than foundational preparation. Choosing the correct activities during the preparation phase is essential for a successful and efficient inspection process.