By CHAN HO-HIM and MATT O’BRIENHONG KONG (AP) — DeepSeek, the Chinese artificial intelligence startup that shook world markets last year, launched preview versions of its latest major update Friday as the AI rivalry between China and the U.S. heats up. DeepSeek’s V4 has been keenly anticipated by users looking to test how it compares to U.S. competitors like OpenAI’s ChatGPT, Anthropic’s Claude and Google’s Gemini. Anthropic and OpenAI have accused DeepSeek of unfairly building its technology off their own. Some industry analysts had expected the new model to arrive more than two months earlier at the start of the…