What should the solutions architect do to meet these requirements?

Explanations:

A NAT instance is a virtual server configured to enable outbound internet traffic from private subnets. However, managing a NAT instance adds operational overhead due to the need for monitoring, scaling, and maintaining the instance, which is not ideal for a strategy focused on minimizing operational overhead.

A NAT gateway is a managed service that allows instances in a private subnet to connect to the internet for updates or to access external resources while preventing incoming traffic from the internet. It reduces operational overhead compared to a NAT instance as it is fully managed by AWS, providing high availability and scalability. Routing private subnet traffic through a NAT gateway is the best practice for secure internet access.

An internet gateway allows direct internet access for resources in public subnets but does not provide secure outbound access for resources in private subnets. Modifying the private subnet route table to direct traffic through an internet gateway would expose private instances to the internet, which contradicts the goal of maximizing security.

A virtual private gateway is used for connecting a VPC to a remote network (like an on-premises network) through a VPN connection, not for internet access. Modifying the private subnet route table to direct traffic through a virtual private gateway does not facilitate outbound internet access and does not meet the requirements for accessing external product catalog information securely.