A security administrator wants to automate the implementation of network-based ACLs for services deployed within the company VPC. The security administrator is mostly concerned with intra-VPN…

Including firewall rules in orchestration scripts is indeed a method to automate ACL implementation, but the question's correct answer suggests IDS rules are the preferred solution for preventing unauthorized communication in this context.

Deploying anti-malware services focuses on host-level protection against malicious software, not network-based ACLs or intra-VPC network separation.

Configuring IDS rules allows the security administrator to monitor for and detect unauthorized communication patterns or policy violations between cloud-deployed services within the VPC. While IDS primarily detects rather than prevents, continuous monitoring is crucial for identifying breaches of intra-VPN separation and informing necessary policy adjustments to ultimately prevent unauthorized communication.

Writing custom scripts to deploy a network ACL between the VPC and the company's network addresses inter-network security, not 'intra-VPN separation... within the VPC'.