An Enhanced Trusted Agent may have which of the following capabilities?

An Enhanced Trusted Agent is typically designed to provide support and capabilities that enhance security and trust within a PKI environment, but with specific limitations regarding sensitive operations. The correct choice here, indicating that an Enhanced Trusted Agent does not have any of the capabilities listed, is appropriate.

For instance, the capability to authorize all user requests would grant excessive control to the agent, potentially leading to security risks and overreach beyond their intended role. Similarly, viewing private keys represents a significant security risk, as private keys are meant to be confidential and safeguarded from unauthorized access to maintain the integrity and confidentiality of the cryptographic processes involved in PKI systems.

The capability to sign certificates is also a high-stakes action that requires a secure and trustworthy process, typically reserved for Certificate Authorities (CAs) rather than a trusted agent. Allowing an Enhanced Trusted Agent to perform such tasks could undermine the trust model that PKI relies on.

Given these perspectives, it becomes clear why the selection of "None of the above" effectively encapsulates the limitations of what an Enhanced Trusted Agent may do, reinforcing their role as supportive rather than authoritative entities within a PKI structure.