Which service would you use to set up a virtual private cloud in AWS?

The correct choice for setting up a virtual private cloud in AWS is Amazon VPC. Amazon Virtual Private Cloud (Amazon VPC) is a fundamental networking service that allows you to define a logically isolated section of the AWS cloud. Within this isolated environment, you can define and control your virtual networking environment including the selection of IP address ranges, creation of subnets, and configuration of route tables and network gateways.

Amazon VPC provides the necessary tools to manage and secure your network infrastructure in the cloud, making it customizable according to your application requirements. It also allows for secure connectivity to your on-premises data center through Virtual Private Network (VPN) connections.

The other services listed do not provide the functionality required for creating a virtual private cloud. Amazon Route 53 is primarily used for DNS management, enabling domain registration, DNS routing, and health checking. AWS CloudFront is a content delivery network (CDN) service used to deliver data, videos, applications, and APIs securely with low latency. Amazon CloudWatch is a monitoring and management service for AWS cloud resources and applications, focusing on the performance monitoring and logging aspects, rather than networking infrastructure setup.