Which container image should be deployed to use the language detection functionality of the Language cognitive service?

The correct choice for deploying the language detection functionality of the Language cognitive service is a specific container image that is explicitly designed for that purpose. The image "mcr.microsoft.com/azure-cognitive-services/textanalytics/language" is tailored to provide language detection capabilities, meaning it includes the necessary components, libraries, and configurations to function effectively with the Language cognitive service's features.

This specificity ensures that when you're aiming to implement functionality such as language detection, you're utilizing the correct service that optimally supports those features, leading to enhanced accuracy and performance. The language-specific container will bring in the functionalities tied directly to text analytics and language detection that aren’t available in broader or unrelated service containers.

Other choices may refer to general or different services that do not focus specifically on language detection. Therefore, for tasks associated strictly with language features, the designated language-specific container is essential for achieving the best results.