Explanation
To create a security policy that will automatically add infected hosts to the infected hosts feed and block further communication through the SRX Series device, you need to add a security intelligence policy to the permit portion of the security policy. A security intelligence policy is a set of rules that defines the actions to be taken for traffic thatmatches a specific category of threat feeds, such as infected hosts, command and control servers, or botnets. By adding a security intelligence policy to the permit portion of the security policy, you can enable the SRX Series device to dynamically update the infected hosts feed based on the advanced anti-malware policy results, and block the traffic from or to the infected hosts. Options B, C, and D are not correct because they do not enable the automatic addition of infected hosts to the feed or the blocking of their communication. References: The answer can be verified from Juniper's official documentation on security intelligence and advanced anti-malware available on their website. Here are some relevant links:
Security Intelligence Feature Guide for Security Devices
Advanced Anti-Malware Feature Guide for Security Devices
Configuring Security Intelligence Policy on the SRX Series Device
[Configuring Advanced Anti-Malware Policy on the SRX Series Device]