What is the best currency to take to China?

I'm planning a trip to China soon and I'm wondering, what is the best currency to take with me? Should I convert my local currency to Chinese yuan before I leave, or is there a more convenient or cost-effective option? Are there any fees or restrictions I should be aware of when exchanging money in China? Additionally, are there any digital or cryptocurrency options that are widely accepted in China that could make my trip easier and more secure?