Which AWS service is designed to help users build conversational interfaces into applications using voice and text?

Explanations:

Amazon Lex is designed specifically to help users build conversational interfaces using voice and text.

Amazon Transcribe converts speech to text but does not provide a full conversational interface.

Amazon Comprehend is used for natural language processing but not for building conversational interfaces.

Amazon Timestream is a time-series database service, unrelated to conversational interfaces.