Less than a month after its debut in Austin, Elon Musk's Tesla robotaxi service is poised to expand its operations around the Texas capital, while adding a controversial new feature to its services. On Wednesday,

Built using huge amounts of computing power at a Tennessee data center, Grok is Musk’s attempt to outdo rivals such as OpenAI’s ChatGPT and Google’s Gemini in building an AI assistant that shows its reasoning before answering a question.