Which of the following should be labeled as high risk in an audit?

Labeling sensitive customer data in a data extension as high risk in an audit is appropriate because it directly pertains to the safeguarding and privacy of personally identifiable information (PII). When handling sensitive data, organizations must comply with various regulations, such as GDPR or CCPA, which enforce strict guidelines on how this information is collected, stored, and processed. The sensitivity of such data places it at higher risk for potential breaches, misuse, and legal implications if not properly managed.

In contrast, while other options also present potential concerns, they do not carry the same level of immediate risk to individual privacy and security. The absence of data retention policies could lead to compliance issues over time, but it is not as directly concerning as the potential for exposing sensitive data. No personalization might affect user engagement but does not directly pose a risk to data security, and a high subscriber volume, while significant from an operational standpoint, does not inherently indicate risk without considering the context of how customer data is handled. Thus, the presence of sensitive customer data in a data extension warrants a high-risk classification due to the implications for data security and privacy.