You are building an app to help students organize their learning materials by topics, using the Azure AI Language service.

You need to analyze each document and suggest groups of documents with common themes based on overlapping sets of important terms.

What should you do first?

Select only one answer.

Extract key phrases for each document.

Extract linked entities for each document.

Use the documents as a data source to support custom question answering.

Use the documents as a data source to support question answering.