How can instances in a private subnet initiate a connection to the internet using a NAT instance?

Instances in a private subnet can initiate a connection to the internet using a NAT (Network Address Translation) instance by using it as a proxy. When instances in the private subnet send their outgoing traffic to the NAT instance, the NAT instance modifies the source IP address of the traffic to its own public IP address before forwarding it to the internet. In doing this, the NAT instance acts as an intermediary, enabling the private instances to access external resources while still not being directly exposed to the internet.

This method ensures that the instances retain their private IP addresses internally while still being able to communicate with external networks. When responses from the internet return to the NAT instance, it translates the destination address back to the original private IP of the requesting instance, allowing the traffic to flow back into the private subnet seamlessly.

The other options do not effectively describe how a NAT instance facilitates internet connectivity for private subnet instances. Forwarding requests through a public IP does not integrate with the NAT instance functionality. Using an Elastic Load Balancer is not applicable because load balancers distribute incoming traffic rather than provide outbound internet access. Directly assigning public IPs to instances in a private subnet defeats the purpose of being in a private subnet, as those instances would then be exposed to the internet directly