Which AWS service provides natural language understanding capabilities for text analysis?

Correct answer: Amazon Comprehend

Option C is correct because Amazon Comprehend is a natural language processing (NLP) service that uses machine learning to find insights and relationships in text, including entity recognition, sentiment analysis, key phrase extraction, and language detection. Option A is wrong because Amazon Polly is a text-to-speech service that converts written text into spoken audio, not a text analysis tool. Option B is incorrect because Amazon Forecast is a time-series forecasting service for predicting future business metrics, unrelated to NLP. Option D is a distractor because Amazon Lex is a conversational interface service for building chatbots and voice interfaces, though it uses NLU internally, it is not the service used for general-purpose text analysis.