Explanation:

Amazon Comprehend is a natural language processing (NLP) service that uses machine learning to find insights and relationships in text. One of its key features is the ability to detect Personally Identifiable Information (PII) in documents, such as names, addresses, phone numbers, email addresses, and other sensitive information.

• Amazon Rekognition is for image and video analysis (facial recognition, object detection).
• Amazon Polly is a text-to-speech service.
• Amazon Translate is a machine translation service.

Only Amazon Comprehend has the specific capability to analyze text documents and identify PII, making it the correct choice for this use case.