Which combination of actions should a solutions architect take to meet these requirements?

Explanations:

Configuring Amazon CloudFront to cache multiple versions of the content allows for efficient delivery of device-specific content. CloudFront can cache different versions of static assets based on cache behavior settings that can be customized by device type.

A Network Load Balancer (NLB) does not support host header routing. This option is not suitable for sending traffic to different instances based on content type as it does not provide the needed flexibility for device-specific content.

Using a Lambda@Edge function to inspect the User-Agent header allows for dynamic content delivery based on the device type. This enables customization of responses based on whether the user is on a mobile device, tablet, or desktop.

While AWS Global Accelerator can improve availability and performance, it does not provide host-based routing functionality as described. NLBs cannot set up host-based routing, so this option is not valid for delivering device-specific content.

Similar to option D, AWS Global Accelerator does not support path-based routing through an NLB. While NLBs can perform path-based routing, this option does not address the requirement for device-specific content delivery effectively.