Which of the following is considered the best way to protect Personally Identifiable Information (PII) from Web application vulnerabilities?

Cryptographic storage protects PII at rest in a database, but does not address vulnerabilities that expose data during web application transmission.

Using encrypted communications protocols such as TLS/HTTPS protects PII while it travels between the client and server, directly mitigating web application vulnerabilities like man-in-the-middle attacks and eavesdropping. This is the most relevant control because web applications primarily expose PII during transmission, and encryption ensures that intercepted data remains unreadable to attackers.

Full disk encryption protects data on physical media from unauthorized physical access, but provides no protection against web application attacks that target data in transit or in use.

A security token addresses authentication and identity verification, not the protection of PII data itself from web application vulnerabilities.