What protects Personally Identifiable Information (PII) accidentally shared by a colleague to the entire company?

The correct answer is C. Data Loss Prevention (out-of-band and inline). In Zero Trust architecture, protection of sensitive data such as Personally Identifiable Information (PII) is handled by controls that understand and govern the content being transmitted, not just the identity of the sender or the existence of a connection. Zscaler’s TLS/SSL inspection reference architecture explicitly identifies Data Loss Prevention (DLP) as a capability that helps prevent sensitive data from leaving the organization . That directly addresses accidental broad sharing, because DLP policies can detect sensitive patterns and stop, restrict, or alert on improper distribution.

SSL/TLS inspection helps make the content visible, but by itself it is not the control that decides whether the sensitive information should be allowed. Identity verification is important for access decisions, but it does not prevent a legitimate user from unintentionally oversharing data. Virtual firewalls also do not provide content-aware protection for PII leakage. Zero Trust requires content-aware controls in addition to identity and context, which is why inline and out-of-band DLP is the correct answer for protecting accidentally shared PII.