According to the Microsoft Azure AI Fundamentals (AI-900) learning path and Azure Text Analytics service documentation, key phrase extraction is a natural language processing (NLP) technique used to automatically identify the main topics or talking points within a text document or a collection of documents. This feature is designed to summarize textual data by detecting the most relevant words or short phrases that capture the essence of the content.

For example, if a document discusses “renewable energy sources such as solar and wind power,” the key phrases extracted might include “renewable energy,” “solar power,” and “wind power.” This helps users quickly understand the primary focus areas of large volumes of text without manual review.

In Azure, the Text Analytics service provides several core NLP capabilities, including:

Key phrase extraction – identifies main concepts or topics.

Entity recognition – detects and categorizes proper names like people, locations, or organizations.

Sentiment analysis – determines the emotional tone (positive, neutral, or negative).

Language detection – identifies the language used in the text.

Since the question specifies identifying main talking points, the correct feature is key phrase extraction, as it focuses on summarizing themes rather than identifying entities or emotions.

Therefore, the verified answer is B. key phrase extraction.