Which command-line is useful for troubleshooting the EPM agent proxy configuration?

The choice of command-line tool that is useful for troubleshooting the EPM agent proxy configuration is indeed "vf_agent -D h." This command is specifically designed to display various configurations and settings related to the EPM agent, including proxy configurations. Using the "-D" flag enables detailed output, which can help identify issues or confirm the current settings, while the "h" parameter often indicates help or a specific output format. Such detailed diagnostics are crucial for pinpointing misconfigurations or connectivity issues with the proxy.

The other options do not directly focus on proxy configuration troubleshooting. For instance, "epm_config -r" is typically used for reconfiguring certain parameters but may not provide the same level of detail specifically for proxy issues. Similarly, "agent_check -proxy" might suggest some sort of validation regarding the state of the proxy but does not delve into the comprehensive configuration output needed for thorough troubleshooting. "cfg_agent -D" could refer to the configuration of the agent, but it does not target the proxy aspect specifically as effectively as the correct choice. Thus, the ability of "vf_agent -D h" to provide detailed insight makes it the suitable command for addressing and troubleshooting proxy configuration within the EPM agent.