A company wants to add a natural-language conversational layer to its BI dashboards so executives can ask questions in text or speech and get answers from the reports. Which combination of AWS services should be used to build this conversational interface? (Choose three.)

To build a natural-language conversational interface for BI dashboards, you need services that can handle speech-to-text, natural language understanding, and text-to-speech. Amazon Transcribe converts spoken language into text, which is essential for speech input. Amazon Lex provides the core conversational AI, understanding user intent from text input and managing the dialogue flow. Amazon Polly synthesizes natural-sounding speech from text, enabling the system to respond audibly. Amazon Comprehend is for advanced text analytics like sentiment analysis or entity recognition, not core conversational flow. Amazon Connect is a cloud contact center service. Alexa for Business manages Alexa devices in an organization, not for building custom conversational interfaces.