Amazon Rekognition's Face Comparison feature enables identity verification by comparing a face in an image with faces in a reference database. This is used for identity verification scenarios such as user authentication, access control, and identity verification processes.

Explanation of other options:

• B. Voice Matching: This is typically part of Amazon Transcribe or other speech services, not Amazon Rekognition
• C. Text-to-Speech: This is part of Amazon Polly service, not Amazon Rekognition
• D. Key-Phrase Extraction: This is part of Amazon Comprehend service for natural language processing, not Amazon Rekognition