What must not be allowed to retrieve information during the cleaning process?

The correct choice emphasizes that during the cleaning process, data recovery utilities must not be allowed to retrieve information. This is crucial because data recovery utilities are specifically designed to restore deleted or lost data, which directly undermines the cleaning process's purpose. When data is being cleaned, the aim is to remove sensitive information in a way that it cannot be recovered by any means, ensuring data confidentiality and security. Allowing data recovery utilities access during this process would pose a significant security risk, as it may enable unauthorized retrieval of information that should have been permanently eliminated.

In contrast, while laboratory resource access, external auditing tools, and system upgrade procedures are important in various operational contexts, they do not have the same direct implication on the integrity of the data cleaning process. Allowing other tools or procedures could be part of standard operations, but the focus on preventing information retrieval during cleaning is paramount to uphold security protocols.