Which VPC component provides a layer of security at the subnet level?

Network ACLs are a feature that provide a layer of security at the subnet level by acting as a firewall to control traffic in and out of one or more subnets. Network ACLs can be configured with rules that allow or deny traffic based on the source and destination IP addresses, ports, and protocols5. Security groups are a feature that provide a layer of security at the instance level by acting as a firewall to control traffic to and from one or more instances. Security groups can be configured with rules that allow or deny traffic based on the source and destination IP addresses, ports, protocols, and security groups. NAT gateways are a feature that enable instances in a private subnet to connect to the internet or other AWS services, but prevent the internet from initiating a connection with those instances. Route tables are a feature that determine where network traffic from a subnet or gateway is directed.