A client is evaluating generative AI and is not sure how much they will need to use it initially. They want to know the difference between the Standard watsonx.ai plan vs. the Essential plan. What is one key difference between the two? A. The Standard plan has all the watsonx.ai models available but the Essential plan only has a subset of the models. B. The two plans have the same capabilities but the Essential plan is a pay-as-you-go plan. C. The Standard plan includes all the features and tooling, whereas the Essential plan does not include watsonx.ai's Synthetic Data Generator. D. The Essential plan is a free tier for clients to try out watsonx.ai. It has a limit of 20 CUH/month whereas the Standard is a pay-as-you-go plan