Which AWS service should the company use to achieve this goal?

Explanations:

AWS IoT Core is a service designed for connecting IoT devices to the cloud, managing data, and enabling device communication. It is not intended for testing mobile applications on devices.

AWS Wavelength is a service that brings AWS services to the edge of the 5G network, enabling ultra-low latency applications. It is focused on network performance rather than mobile app testing.

AWS Device Farm is a testing service that allows developers to test their mobile apps on a wide range of real devices hosted in the AWS Cloud. It provides the necessary environment to evaluate app performance and functionality across different platforms.

AWS Direct Connect is a network service that provides a dedicated connection from on-premises data centers to AWS. It is primarily used for establishing reliable and high-bandwidth network connections, not for testing mobile applications.